A new species of hominin hits the news. What is it and what does it mean?

“Hominins” (formerly “hominids”), comprise all species, extinct and living (the latter is only H. sapiens), that fell on the side of the lineage that produced modern humans after the divergence of that lineage from the lineage leading to modern chimpanzees (our closest living relatives). Not all hominins fall in the genus Homo, of course: we have Australopithecus, Sahelanthropus, Paranthropus, and several other genera whose members went extinct without issue. Further, not all members of the genus Homo need have been our ancestors: several species might have lived—and probably did live— at the same time, as the chart below indicates. And some of these species probably went extinct without issue, and so aren’t our ancestors:

Screen Shot 2015-09-10 at 8.44.52 AM

We are in fact not sure what earlier species evolved into Homo sapiens. Homo erectus, with a fairly big brain and widspread geographic distribution, might be a candidate, but we’re not even sure about that. Fossils are generally scarce, their characteristics overlap with fossils from other places, and we’re often unable to distinguish different species from simple variation among geographic localities within a single species—the brand of variation that is sometimes called “racial variation”.

This has led to a tendency to name every new fossil as a separate species (who wants to just describe yet another specimen of H. habilis?), which in turns leads to acrimonious debate about what species is what, and that then leads to the Big Debate about “what species was on the lineage leading to modern humans?”

Unfortunately, we can’t yet answer that last question, nor one closely connected with it: “When did we become human?” That question is nonsensical, I think, for it depends on exactly what you mean by “human”. If it involves purely physical traits, then we can at least in principle pinpoint such a time, though which traits you choose will themselves be arbitrary. If it’s mental traits or behavior, that’s even harder, for such things don’t fossilize. Sometimes, however, we might find instances of ritualized behavior, as in the burial of Neanderthal bodies and the anointing of skeletons with ochre. Did that make us human? Or was it speech, something notoriously difficult to discern from fossils? Or was it the complexity of cogitation or the development of the “intentional stance,” something almost impossible to discern from skeletons?

At any rate, a new species of hominin, H. naledi, has been described in a new paper (reference at bottom, free access) in eLife. It was written by Lee Berger et al. (the “et al.” are about 60 authors!), and describes a collection of 15 skeletons discovered together in a cave in South Africa. This is a remarkably complete collection of skeletons, and the gist of the paper is described at both the BBC and the New York Times. What I put below is distilled largely from these secondary sources, though I’ve had a look at the paper as well.

First, what’s notable is that there are so many skeletons, which—unlike many hominin fossils, found as partial skulls or other bones—allowed the authors to piece together a complete view of the species’ skeletal traits. Here are some of the remains in a photo by John Hawks from the BBC site:

_85448683_01-homo-naledi-bone-table-vertical-john-hawks-cc-by

Now why is this considered a new species of hominin? Well, it’s a mosaic of primitive and advanced traits, as the paper itself says:

H. naledi presents yet a different combination of traits. This species combines a humanlike body size and stature with an australopith-sized brain; features of the shoulder and hand apparently well-suited for climbing with humanlike hand and wrist adaptations for manipulation; australopith-like hip mechanics with humanlike terrestrial adaptations of the foot and lower limb; small dentition with primitive dental proportions.

How old is this species? We don’t know. The cave can be dated, and could be as old as 3 million years, and the authors say likewise that these fossils could be three million years old, antedating the earliest described species of HomoH. habilis—by nearly a million years. But that’s the age of the cave, not of the fossils. The fossils could be two million, one million, or even 500,000 years old. (H. floresiensis, the “hobbit,” which was about three feet tall with a tiny brain and totally non-modern skeleton, lived as recently as 12,000 years ago!)

Like australopithecines, H. naledi had a very small skull but a largely modern postcranial skeleton. Why isn’t it an australopithecine? Largely because its brain is bigger (by about 25%), its molars are very small (australopithecines had big molars) and there are skull characteristics that lump it with species like H. erectus. But many of the traits still fall within the range of australopithecines. Here are some additional drawings from the BBC showing “modern” traits mixed with primitive ones:


skulls_976

The curved fingers may imply that this species was partly arboreal, i.e., that it still climbed trees:
hands_976

The shape of the foot suggests, though, that the species was at least largely bipedal, a modern trait. (Australopithecines were also bipedal, as we know from the Laetoli footprints). feet_976

So let’s get to the three big questions. Two of them are answered erroneously in the title of the New York Times piece: “New species of human ancestor is found in a South African cave.” This is bad journalism on two counts: we have no idea whether H. naledi was on the lineage leading to H. sapiens. That means that we can’t say with any assurance that it was one of our ancestors. All we can say is that it was related to our ancestors.  Second, we don’t know for sure if it’s a new species, for that’s a judgment call. But let’s look in a bit more depth.

Is H. naledi a new species? Evolutionary biologists define a “species” as a group of individuals or populations separated from other such groups by reproductive isolating barriers that prevent them from successfully exchanging genes. Since we don’t know this from fossil hominins (though we do for Neanderthals vs. H. sapiens, which clearly did exchange genes and thus belong in the same species), we usually make such judgments solely on morphological grounds: does this species look different from other described hominin species? The authors’ judgment, based on the many skeletons and fragments they have, is that it does, and so they give it a new name.

That, however, doesn’t convince me fully, for the differences are small, and, as the authors note, many of the feature resemble those of H. habilis or early H. erectus.  That there may be diagnostic differences in some traits doesn’t convince me that this is a new species, for this could simply be a localized geographic variant—perhaps even a genetically related band—of a species already described. So I think it’s a bit premature to give it a new name. But I’m not particularly concerned about that. What’s more important is to get an accurate date for this fossil, for if it really is 3 million years old, that would certainly push back the origin of the genus Homo by a long period.

Is H. naledi our ancestor? As I said above, we don’t have the slightest idea. No journalist should state that this group is on the lineage leading to modern humans.

Did H. naledi practice ritual burial? This seems more likely, as all the skeletons are piled up together, though I don’t see any sign that there was any superstition involved in this practice. Perhaps they were sequestering the dead people away from others to avoid the stench. And even if they were putting the dead together (these dead involved hominins of all ages, by the way), this says little about the mentality of this species beyond the fact that they recognized the dead as different from the living. Again, it’s way premature to say that these things were “human,” as if they had a mentation or a spirituality resembling that of modern humans.  This statement by Lee Berger, then, which appeared in the BBC report, seems to me largely meaningless, for “what it is to be human” depends completely on what you mean by “human”:

Prof Berger believes that the discovery of a creature that has such a mix of modern and primitive features should make scientists rethink the definition of what it is to be human – so much so that he himself is reluctant to describe naledi as human.

I don’t even know if scientists have a consensus view of “what it is to be human”!

Now I don’t mean to be highly critical of the paper, as the description of the trove of skeletons is remarkable, and the analysis and description of differences from existing species is very good. I suppose what I’m criticizing here is largely the press coverage of this find, but also the willingness of the investigators to give this group a new species name when its age isn’t even known, and when it could simply be a geographical variant of an existing species—something that would be clearer if we had dates! And I am not an expert in human evolution, so I could be missing something, or have erred in my opinion. As usual, I’m willing to be corrected. But for the moment, caveat lector.

________

Berger, L. R. et al. 2015. Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa. eLife: 2015;4:e09560, DOI http://dx.doi.org/10.7554/eLife.09560. 

256 Comments

  1. Colin
    Posted September 10, 2015 at 10:07 am | Permalink

    I think I’ve already seen articles with titles such as “Human evolution re-written!” Bordering on click-bait.

    • Posted September 10, 2015 at 12:33 pm | Permalink

      You won’t believe these sexy new human ancestors!

      • GBJames
        Posted September 10, 2015 at 12:39 pm | Permalink

        They found dozens of bones. You won’t believe what happened next!

        • Colin
          Posted September 10, 2015 at 12:45 pm | Permalink

          LOL

          • Mark
            Posted September 10, 2015 at 1:40 pm | Permalink

            “Team of Women cavers find new man”

            • HaggisForBrains
              Posted September 11, 2015 at 2:57 am | Permalink

              😀

            • Diana MacPherson
              Posted September 12, 2015 at 12:30 pm | Permalink

              Winner!

  2. Kevin
    Posted September 10, 2015 at 10:07 am | Permalink

    It is astonishing that we do not walk the planet with other sentient beings from our distant relatives. Of course, cruelty for ‘others’ may make that situation inevitably scarce. On the other hand, we have been intensely curious and sharing our wonder is part of what makes us want to be around ‘others’ hoping they will appreciate what we wonder about.

    • Posted September 10, 2015 at 10:22 am | Permalink

      I don’t think there’s any question but that the other great apes, at a bare minimum, are sentient.

      What they don’t have is their own highly-developed language or the technology that language breeds.

      b&

      • Colin
        Posted September 10, 2015 at 10:30 am | Permalink

        Yes, I’ve often said to those (invariably religious) folks who don’t accept the fact of evolution and who view humans as separate from the rest of the animal kingdom: “Imagine a hypothetical large group of apes, chimps, bonobos – whatever – and you were magically able to suddenly endow them with language. Imagine just how enormously and quickly the trajectory of their lives would be altered.”

    • squidmaster
      Posted September 10, 2015 at 11:40 am | Permalink

      If by ‘sentient’ you mean ‘having an internal neural representation of the self as separate from other individual and having a representation of those other individuals as having predictable behavior’ then chimps (including bonobos) very clearly are ‘sentient’. Their sentience is quantitatively different from humans, but probably qualitatively similar (based on highly similar brains).

      Other species have elements of ‘sentience’ or a theory of mind (altering one’s behavior based on the inferred likely behavior of a conspecific, based on past experience of one’s own behavior). For example, scrub jays cache food and will steal from one another, given the opportunity. Thus, they frequently re-cache food. In experimental situations, jays who have previously stolen from other jays are more likely to re-cache food when observed by a second jay than if they had not previously stolen from other jays. To anthropomorphize a bit: Jay Jill (an inveterate theif) notices Jay Jake watching while she hides some food. After Jay Jake leaves, Jay Jill quickly re-hides the food because she assumes that Jake will act like her and try to steal the food when she isn’t looking.

      Now, I think that the chimp evidence is interesting, but then chimps are our closest non-human relatives. The observations with birds are more interesting because our last common ancestor with dinosaurs lived over 300 million years ago. That’s a lot of time for brain function to diverge. And yet, elements of sentience have emerged in both lineages (although some dispute the sentience of the Republicsn clade of Homo sapiens).

      I suspect that if other hominins had survived to the present day, we’d have more salient examples of gradual development of the elements of sentience we see in ourselves. Consciousness is, at base, a perception of what our brain just did (including what it just ‘considered’ doing). It apparently takes a fairly complex brain to model it’s own behavior and how it might interact with other brains that behave similarly.

    • Mark Sturtevant
      Posted September 10, 2015 at 3:40 pm | Permalink

      That we are alone is likely b/c we murdered them, either directly or indirectly. I have no evidence, but it is easy to find detailed illustrations that show that as cranial size increases, so does sophistication and variety of tool use. And, most tellingly, the older kinds of tools and their makers steadily disappear. in their wake.

    • Torbjörn Larsson
      Posted September 11, 2015 at 5:10 am | Permalink

      We did have relatives, then we crossed them back into us. (Except for H. floresiensis it seems, they never got the chance.)

      I guess we can blame our huge social abilities.

      • Torbjörn Larsson
        Posted September 11, 2015 at 5:10 am | Permalink

        Sigh. More htmlos.

  3. Matt G
    Posted September 10, 2015 at 10:09 am | Permalink

    There is a 2 hour documentary on NOVA which is available for streaming now (it will be broadcast next week).

    • Kevin
      Posted September 10, 2015 at 11:23 am | Permalink

      If you are referring to the ‘Becoming Human’ series they are amazing. Every kid in the world should see them.

      • Matt G
        Posted September 10, 2015 at 11:44 am | Permalink

        No, this one is called “Dawn of Humanity” And it was released today.

      • Mark Sturtevant
        Posted September 10, 2015 at 3:43 pm | Permalink

        That one is very good, but I have noticed that they tend to speculate that as different kinds of humans encounter each other that they basically start singing kumbaya and are all nicey nice.
        Not likely, in my opinion.

  4. Posted September 10, 2015 at 10:09 am | Permalink

    Unfortunately, we can’t yet answer that last question, nor one closely connected with it: “When did we become human?” That question is nonsensical, I think, for it depends on exactly what you mean by “human”.

    I’ll answer that as soon as somebody identifies for me the exact wavelength that divides the blue part of the spectrum from the green — the line you’d draw on a rainbow, where, to the one side, the color is unquestionably blue, and, the other side, green.

    b&

    • jeremyp
      Posted September 10, 2015 at 10:51 am | Permalink

      It’s easy. For me, it’s just after the second cup of coffee of the morning.

      • Mark R.
        Posted September 10, 2015 at 11:31 am | Permalink

        I think, like in evolution, there is no line…just minute graduation. Then again, the line between blue and green might be turquoise, or ultramarine…only kidding.

      • Posted September 10, 2015 at 11:49 am | Permalink

        You’re lucky. For some, it’s not until after the sixth beer….

        b&

    • Posted September 10, 2015 at 6:10 pm | Permalink

      Likewise, find the specific moment, hell let’s go down to the Planck unit of time when a person becomes an adult. We may define that as 18 years old, but you’d sure be hard pressed to demonstrate what’s different about that 18 year old from the 18 year old that existed a moment before.

      • Posted September 10, 2015 at 6:11 pm | Permalink

        *that should be “almost 18 year old that existed a moment before”

      • Posted September 10, 2015 at 6:25 pm | Permalink

        Even 18 isn’t an absolute dividing line between child and adult. Twenty-year-olds can’t legally drink — and even that’s not the dividing line. You’ve got to wait until 25 to run for Congress, 30 for the Senate, and 35 for the Presidency. And that’s just the big government numbers….

        b&

        • een
          Posted September 10, 2015 at 7:37 pm | Permalink

          Obviously not all human beings are of the same opinion here. On the legal age of drinking, here in NZ one can legally purchase alcohol at the age of 18.

          As my brother-in-law the lawyer is fond of reminding us, in NZ one can actually drink alcohol at any age. It’s only restricted on purchase.

          • Posted September 10, 2015 at 7:56 pm | Permalink

            Serving alcohol to a minor can get you in some deep shit here in the States. And especially buying alcohol for a minor…somebody asks you to buy a six-pack because of lack of ID, you’d be a damned fool to comply.

            b&

  5. colnago80
    Posted September 10, 2015 at 10:13 am | Permalink

    The article in the Guardian said that the brain case indicated a brain about 560cc, somewhat larger then Australopithecus Afarensis, with a brain case of ~400cc.

    • Posted September 10, 2015 at 10:21 am | Permalink

      Yes, but it overlaps with that of H. habilis. But I’ve added the brain-size distinction, thanks!

  6. Jonathan Smith
    Posted September 10, 2015 at 10:25 am | Permalink

    “When did we become human?” Well it has to be when God decided to invent the soul and place it only in humans. Well, that’s what the Pope says so it must be true.

    • BobTerrace
      Posted September 10, 2015 at 11:20 am | Permalink

      When did we become human?

      By my definition only some members of H sapiens are.

    • Mark Sturtevant
      Posted September 10, 2015 at 3:45 pm | Permalink

      There is this now old factoid that we share 50% of our genes with bananas. I am willing to believe that some of use are more than half bananas.

  7. Posted September 10, 2015 at 10:28 am | Permalink

    This is one of those science posts which gave me great joy to read. But I don’t know enough to make a comment other than “wow”.

    So, your science posts do get read, even if the number of comments is small.

  8. gravelinspector-Aidan
    Posted September 10, 2015 at 10:36 am | Permalink

    One interesting aspect of this is the putting together and use of an “undernourished dwarf” team of archaeologists to actually excavate the cave. I saw appeals for volunteers for this a year or two ago in the press – I forget if it was the caving press, or something slightly less “specialist” than “Mud and Skintight Rubber suits Monthly”, but there was a perceived need for young, fit, agile and above all small anthropology and/ or archaeology or other related students, who would find it appreciably easier to get into and out of the cave to carry out the excavation to the required standards.
    (The nickname “undernourished dwarfs” harks back to certain appalling cave rescue incidents in the 1960s, during which the cave rescue volunteers realised that they really needed to be able to put together teams of “undernourished psychotic dwarfs” (in I think Bob Leakey’s words, who was well on the psychotic side of hard, but was well over 6ft long and therfore couldn’t attend some rescues without breaking his thigh bones on the way to attend the casualty).
    This discovery is a wonderful result for the team assembled, and amply justifies the effort to assemble such expertise. Inevitably, most of them will have been undergraduates or Masters students, and so should have set themselves up nicely for a career, but one hopes they can keep the team and experience together because there are probably more sites that could benefit from such attentions.
    On second thoughts, it’s not quite the first time caving specialists have been needed for such excavations. A number of archaeologists had to become cave divers to examine and document la Grotte Cosquer in the 1980s. After an initial discovery by cave divers, some years of work were done by archaeologists trained to cave dive, but since the death of non-cave divers in the system, it has been gated. TTBOMK, no “dry” entrance has been reported. But that’s diving in a cave, which while it has it’s own hazards, is not generally a tight, awkward squeeze such as abounded on the approaches to the “naledi” cave.
    That the present entrance to the chamber is “undernourished dwarf” terrain doesn’t mean that this is how the hominoids got the corpses there – the access route they used could have been blocked by flowstone (stalactites, stalagmites, and related deposits), rockfall, sediment influx (there has certainly been sediment influx into the chamber to cover up the lower layers of bodies) or all of the above. Working out the erosion and infill history of a cave is complicated enough, without having archaeologists crawling all over the site. I’m sure they’ll get it sorted out in due course, but it’s relatively low priority at the moment. Though it could be an indicator for finding new deposits, once this one has been thoroughly mined out.
    Off to read up the actual archaeology now. Fascinating!

    • Diane G.
      Posted September 10, 2015 at 1:24 pm | Permalink

      Fascinating, Aidan!

      • HaggisForBrains
        Posted September 11, 2015 at 3:24 am | Permalink

        Fascinating Aidan

        • gravelinspector-Aidan
          Posted September 12, 2015 at 9:59 am | Permalink

          I’ve heard of them, but never actually heard them before. Very Radio 2.

        • Diane G.
          Posted September 15, 2015 at 5:17 am | Permalink

          Hilarious!!!

          Thanks for the link!

  9. GBJames
    Posted September 10, 2015 at 10:37 am | Permalink

    Great post.

  10. darrelle
    Posted September 10, 2015 at 10:37 am | Permalink

    I’m curious why the remains haven’t been dated yet. Reluctance to sacrifice the material? Just haven’t taken the time yet?

    In any case, an exciting find. Such a wealth of remains in one location.

    • nickswearsky
      Posted September 10, 2015 at 10:43 am | Permalink

      The fossils cannot be dated directly and are too old for radiocarbon dating. Other radiometric techniques can be applied to surrounding matrix but datable materials are absent. Many radiometric techniques for fossils older than about 1 million years require volcanic rocks. The cave sites of South Africa are not volcanic in origin and are well-known for the complex stratigraphy which makes dating difficult at best.

      • darrelle
        Posted September 10, 2015 at 11:09 am | Permalink

        Thank you for the explanation.

      • Diane G.
        Posted September 10, 2015 at 1:25 pm | Permalink

        Had no idea it was that complicated!

        • gravelinspector-Aidan
          Posted September 10, 2015 at 1:29 pm | Permalink

          Oh, it’s a lot more complicated than that!

      • gravelinspector-Aidan
        Posted September 10, 2015 at 1:32 pm | Permalink

        The fossils cannot be dated directly and are too old for radiocarbon dating.

        What is really needed is to date the act of sedimentation around the bones. And the act of sedimentation below the bones. Then the act of arrival of the bones is bracketed.

    • Posted September 10, 2015 at 10:53 am | Permalink

      Past about 50,000 years, carbon-14 dating doesn’t work. There are good methods for dating older igneous rocks, but in most cases the date at which sedimentary rock was deposited can’t be determined directly. (Some methods do date sedimentary rocks in unusual situations. Obviously this isn’t one of them.)

      • darrelle
        Posted September 10, 2015 at 11:09 am | Permalink

        Thanks.

        • Mark R.
          Posted September 10, 2015 at 11:34 am | Permalink

          That was going to be my question too, and for some reason, I thought (with all the myriad dating techniques) that we could date fossils from any epoch. So without that crucial data, these will continue to be a complete mystery. Sort of sad I think.

          • Diane G.
            Posted September 10, 2015 at 1:27 pm | Permalink

            “…and for some reason, I thought (with all the myriad dating techniques) that we could date fossils from any epoch.”

            Same here.

            • Dave
              Posted September 10, 2015 at 4:21 pm | Permalink

              It will help if they can find some associated animal fossils. The sequence of mammalian faunas in both eastern and southern Africa is fairly well-known now. The species that were living alongside these new hominids should give at least a ballpark estimate of age if they can be matched with fossils from dateable (i.e. volcanic) formations in east Africa.

              I haven’t read these new papers so I don’t know if they mention any associated fauna. Certainly the original australopithecine caves in South Africa were stuffed with animal fossils, so there may be some grounds for optimism.

              • Diane G.
                Posted September 12, 2015 at 2:19 am | Permalink

                Thanks, Dave! I’m learning so much fascinating stuff in this thread!

      • John Scanlon, FCD
        Posted September 11, 2015 at 9:43 am | Permalink

        The flowstones capping parts of the bone-bearing layers can possibly (probably?) be dated using U-Pb, but this hasn’t been achieved yet because the samples analysed so far are dirty, containing high and variable amounts of common lead (Dirks et al., p.14). A date on the flowstone would provide a minimum age, but may be much younger than the fossils.

        If any of the sediment in the cave was washed in from the surface, then it might be dated using fossil sunlight. This possibility isn’t mentioned in the papers, but it’s likely that someone is looking into it.

        • John Scanlon, FCD
          Posted September 11, 2015 at 10:55 am | Permalink

          (I see this has been discussed already, below)

        • Diane G.
          Posted September 15, 2015 at 7:29 am | Permalink

          “Optical Dating”

          That is so cool!!

          • GBJames
            Posted September 15, 2015 at 8:35 am | Permalink

            Unavailable to the blind.

            • Diane G.
              Posted September 15, 2015 at 4:02 pm | Permalink

              Two words: blind date.

              Duh!

  11. Mark Sturtevant
    Posted September 10, 2015 at 10:47 am | Permalink

    I do not know how the bodies were arranged in the cave, but if they were piled together it seems possible to me that this was a large family group that became trapped in the cave, and they died there. I had read that they seemed remarkably healthy, so maybe they were not in there voluntarily.

    • Mark R.
      Posted September 10, 2015 at 11:42 am | Permalink

      I thought this too, but wondered what could trap a large group like this in a cave until they died. They would have to be trapped for at least 3 days (assuming they had no water). Maybe they couldn’t last that long, but I still couldn’t think of a feasible scenario that would trap so many. A cave-in is the best answer I can think of. What about violent volcanic activity? Or trapped by a predator(s)? I guess we’ll never know.

      • Mark Sturtevant
        Posted September 10, 2015 at 3:52 pm | Permalink

        Or why they would go thru a narrow passage in the first place. Still, the placement of the bodies would be important since if they are ‘arranged’ then that would be very suspicious. If all tangled together then that could mean anything.

    • Marella
      Posted September 11, 2015 at 1:56 am | Permalink

      They report that there are thousands of individuals still to be excavated, so not a single family getting unlucky.

      • Torbjörn Larsson
        Posted September 11, 2015 at 5:18 am | Permalink

        Don’t you mean individual fossils rather than individual hominins? Having thousands of individuals die in a small crevice in the same cave would be unprecedented and seems small likelihood.

        • Marella
          Posted September 11, 2015 at 8:12 pm | Permalink

          Yes, yes I do.

    • Torbjörn Larsson
      Posted September 11, 2015 at 5:20 am | Permalink

      Their dentition seems caries free. For what that is worth as early health indicator,
      I don’t think it bears on their health as much as it would today.

  12. nickswearsky
    Posted September 10, 2015 at 10:49 am | Permalink

    I’m curious as to how these fossil compare to Australopithecus sediba, which Berger discovered and described from South Africa a couple of year ago. It seems quite similar, with a mosaic of primitive and Homolike features. I’m disappointed by the lack of a date for the fossils, but not surprised, given the site. Still, they need to get a handle on how old this species is. Is it an ancestor or just a late hominin contemporary of other Homo that is ancestral to us? I’m also very skeptical of the idea that this is a burial. That behavior is just not seen, even among early Homo sapiens. It would be very odd in an even earlier hominin. I suspect a catastrophic event that wiped out a group.

    • gravelinspector-Aidan
      Posted September 12, 2015 at 10:06 am | Permalink

      Then you have to have a group containing very young and old simultaneously, in a non-residence context. And despite my scepticism expressed up or down thread about the actual access route, the fact remains that quite a few eyes have looked, hard, for alternative entrances to the chamber and not found one. That makes it unlikely that the actual access route was fit for bicycling trombonists, even if it wasn’t as hard as the current access.

  13. Jay Hadden
    Posted September 10, 2015 at 11:00 am | Permalink

    It’s the same problem we encounter with the identification of all chrono species; at some point on the continuum a parent would give birth to offspring identified as a different species (or genera in the case of australopithecines/homo). Obviously, all parent/offspring matings could produce viable offspring. However, I would assume that if I traveled back in time I would not be capable of reproducing with an australopithecine. So yes, the divisions can be somewhat arbitrary but they also reflect something real at the extremes (it’s identifying the space between extremes that is difficult).

  14. Richard C
    Posted September 10, 2015 at 11:02 am | Permalink

    Exciting find!

  15. gravelinspector-Aidan
    Posted September 10, 2015 at 11:06 am | Permalink

    Other paper : “ Geological and taphonomic context for the new hominin species Homo naledi from the Dinaledi Chamber, South Africa” and as a PDF.
    I don’t have any automatic sign-in for this journal, so if I can get the PDF, anyone else can. Oh, is there any SI? There are mentions of supplementary files in the text, but I’ll get to them later. An interesting and unusual aspect is the presence of sections for “Decision letter” and “Author response” in the main (no-PDF) version of the paper. The Author response includes comments in response to the reviewer’s comments. I’ll quote the start :

    In revising the paper, we have made the following changes:
    We have changed the title, most notably by removal referral to purposeful burial.
    We have toned down our interpretation in the Abstract and have allowed for alternative interpretations, although we still state our preferred interpretation.
    We have extended the Introduction and combined a general introduction to cave deposits in the CoH in South Africa with an extended introduction to the Rising Star cave system.

    Now, that is quite interesting as an insight into the process of publication. Very interesting. I am certain that many of the criticisms that will be made of these papers will actually be addressed in those comments. Critics don’t read the effing paper – film at eleven!
    Chris Stringer (does he need introduction? The nhm.ac.uk human fossils chief bod) does an introduction piece at elife : Human evolution:
    The many mysteries of Homo naledi
    and PDF.
    And now I need to read the papers myself.

    • gravelinspector-Aidan
      Posted September 10, 2015 at 11:25 am | Permalink

      Stringer’s last words :

      While many have concentrated on East Africa as the key and perhaps sole region for the origins of the genus Homo, the continuing surprises emerging from further south remind us that Africa is a huge continent that even now is largely unexplored for its early human fossils.

      Very true.
      He also expresses surprise at the “apparent lack of dating efforts” – which I am sure are in work. In the “geology and taphonomy” paper, I saw some very detailed drawings of the flowstone layers in the chamber, on it’s walls and interleaving with various layers of the sediment fill. That is the sort of detail that I’d be needing to record to really “do the work” on deducing the cave’s history. So I think it is just “work in progress”.
      Inhale … and the other two papers.

      • Matt G
        Posted September 10, 2015 at 11:47 am | Permalink

        We are very fortunate that human remains have survived to the present to the extent that they have. I’ve heard it said that there are NO chimpanzee fossils, owing to the climate where chimps reside.

        • gravelinspector-Aidan
          Posted September 10, 2015 at 1:27 pm | Permalink

          Well, forest soil chemistry rather than climate. Relatively acid soil digests the mineral component of the bones, and the bugs eat the rest.
          And it’s time to delve into the “taphonomy” paper, which is where the “burial behaviour” claims must reside.

    • gravelinspector-Aidan
      Posted September 10, 2015 at 11:36 am | Permalink

      Stringer thinks the material looks quite similar to the Dimanisi (Georgia) 1.8Ma Homo erectus material, BUT the sheer wealth of bones may mean that a LOT of smaller hominin material needs to be re-evaluated. It’s the old “lumpers versus splitters” problem – when you get a lot more material, you may find that what you previously thought was two representatives of different species are members of a continuum. Or, to quote the (a) polite version of an old song, “Bless ’em all / the long and the short and the tall.”
      And it’s all pending on the dating.

      • gravelinspector-Aidan
        Posted September 10, 2015 at 11:54 am | Permalink

        And onto the “bones” paper.
        They mention the presence of a few rodent bones (hardly unexpected in a cave, particularly one 30m underground, with rotting meat) and six bird bones.
        I’m not suggesting this, but I BET (1 pint, 2:3 odds) someone is going to suggest that the “funeral” activities (suggested, but even the authors admit, NOT demonstrated) included bird carcasses. Say, a bird wing for waving around. It’s an attractive idea. But I can just as well envisage Mr Ratty dragging Mr Pigeon’s wing down there for a chow. But that won’t stop sensationalist TV programmes, I bet.

        • Posted September 10, 2015 at 11:58 am | Permalink

          If you’ve made it that far…have they addressed the possibility that they were all trapped alive in a catastrophic event, as some others have suggested in this thread? Is there any way of knowing the relative times of death? Or, for that matter, any forensic clues as to cause of death?

          If the dead were added over a span of generations, that would be a most compelling fact….

          b&

          • gravelinspector-Aidan
            Posted September 10, 2015 at 12:27 pm | Permalink

            P17 of 35 in the first paper, and to be honest, I think I’m going to read the second (geology and taphonomy) paper, which will contain the stratigraphic detail, with a pint in my hand.
            There’s some comments on the shape of the femur – otherwise unknown ridges on front and rear of the femur – which probably speak to gait. But I haven’t got to that bit yet.

            • gravelinspector-Aidan
              Posted September 10, 2015 at 12:30 pm | Permalink

              Feet, feet, feet. A litany of “[species name] doesn’t have well-enough preserved feet for meaningful comparison with OUR material!”
              More crowing than a telegraph wire full of corvids. But true nonetheless.

            • Posted September 10, 2015 at 4:11 pm | Permalink

              Reading through some of the other speculation…two more possibilities come to mind if they all died together in the cave at the same time.

              The first, and I think rather unlikely but it came to mind, was some ancient analogue of the modern doomsday cult. They went in the cave seeking some sort of nirvana and never left.

              The second grew out of the first…and I think is not at all unlikely should it turn out to be a single group who died together in the cave.

              And that would be that they were driven into the cave by other hominins. I can’t think of any other threat that could conceivably force such an action and sustain a blockade long enough for the victims to starve.

              Come to think of it…even if the deaths happened over a span of generations…it could still be something along those lines, with the future fossils driven into the cave for who-knows-what reason. Maybe sacrifices to appease an ancient superstition, or maybe they contracted some visibly disfiguring disease and this was a result of safely driving them away where they couldn’t sneak back from.

              Anyway, I’d really love to learn of any forensic analysis that might indicate both cause of death and general health before death.

              b&

              • gravelinspector-Aidan
                Posted September 10, 2015 at 7:08 pm | Permalink

                if they all died together in the cave at the same time.

                Articulated sections of bodies (to be more precise, hands) underlay near-vertical long bones, which underlay articulated remains.
                Single-event explanations have problems with multi-phase deposits like that. Like “how?”

              • Posted September 10, 2015 at 7:54 pm | Permalink

                I’m trying to visualize the geometry.

                Would it be consistent with laying on top of the hands, whether face-up or face-down? And perhaps even having the hands tied? Or being hogtied or the like?

                I suppose I’m asking…if the hands were…ah…within reach of the rest of the bones.

                I know I’m painting a rather gruesome picture, but we know our even more recent history (and present) isn’t exactly all sweetness and roses.

                b&

              • gravelinspector-Aidan
                Posted September 11, 2015 at 2:23 pm | Permalink

                At this moment, it’s not even sure if the three sets of skeletal elements are even from the same gender of humanoid, let alone from the same individual. (I’m on the work’s computer, and the PDFs are on the other one. But the tables of finds are in SI files I didn’t download.)

              • Torbjörn Larsson
                Posted September 11, 2015 at 5:35 am | Permalink

                Re sweetness and roses, except for the spanish find of agrarians from some thousands years ago and the neanderthal violence find, there is a lack of signs of violence. (And perhaps we should count the Kennewick Man with his healed wounds.) In modern times there were both sacrificial rites (bog people, meso-indian finds) and wars that added much such material, but those seem to be outcomes of more more frequent migration and increasing population density.

                The statistics is still bad, but the first one that looked at hominin interspecies killing found comparable levels in all looked at species (humans, chimps, bonobos). I wouldn’t expect that to have changed through deep history, or be much of a factor. Individuals mostly die from other causes.

                Frankly, I find this line of hypotheses colored by unwarranted bias.

              • Diane G.
                Posted September 12, 2015 at 3:20 am | Permalink

                Possibly less violent possibilities: something along the lines of mischievous kid naledis managing to clamber down into or fall into this difficult-to-access chamber; distraught parents/extended family members/just other tribespeople follow suit in an attempt to rescue the kiddos, get trapped themselves.

                People still do crazy things to end up dead together; it’s not uncommon that when one farmworker is overcome by silo gas, another one will enter and be overcome while trying to rescue the first one, a third will do the same while going after the first two…

                Speaking of the chamber itself–amongst other disincentives, wouldn’t it have been just darker’n hell? Does that sound like a place that would have been used for burial ceremonies? (Beyond just dumping bodies down a hole, I mean.)

                Speaking of gases (wasn’t I?)–would there ever have been any sort of toxic fumes associated with these cave chambers?

                These people didn’t have fire, did they? (So they likely couldn’t have accidentally asphyxiated themselves…?)

                Ignorant Я I.

          • nickswearsky
            Posted September 10, 2015 at 1:57 pm | Permalink

            They have a lot of bones from several individuals of varied ages (juveniles to aged adults, many small foot and hand bones present means bones were not transported by water. No other animals present suggests this was not some open hole that many animals could have fallen into. Sediments are soft clays that do not indicate flowing water. Still, I think best explanation is a group traveling together sheltered in one spot and were killed in a single event. The absence of “background noise” of other animal fossils supports this (Johanson proposed same scenario for the “first family.”). Gradual deposition over months or years, it’s hard to understand how no other critters ended up there or bones were transported over time by flood waters.

          • gravelinspector-Aidan
            Posted September 10, 2015 at 6:55 pm | Permalink

            There is suggestive evidence – some long bones are oriented at high angles to the preferred orientation of most bones, and to the gravity field. That sniffs of post-mortem rearrangement, but doesn’t preclude the effects of post-depositional sediment movement (they repeatedly refer to “sediment drains”, which makes me think of at least intermittent fluid drainage in the chamber.

        • gravelinspector-Aidan
          Posted September 10, 2015 at 12:11 pm | Permalink

          Hmmm, there’s a term I’ve not met before. “Apical tuft”. I could figure out what I thought it meant, and Wikipedia concurs, which is good enough for me.

          The flat, wide expansions found at the tips of the distal phalanges are called apical tufts. They support the fingertip pads and nails.

          So, that’s pretty interesting from a manual dexterity and potentially tool-use point of view. Anyone know how (say) Pan compares with Homo in this respect?

          • gravelinspector-Aidan
            Posted September 10, 2015 at 12:21 pm | Permalink

            And indeed, the authors thought that “apical tufts” were worth paying attention to.

            H1 (this hand was found in an articulated position) also differs from all other known hominins except H.neanderthalensis in having non-pollical distal phalanges (tips of fingers, but not thumb-tip) with mediolaterally broad apical tufts (relative to length)

            (p17 of 35)

            • Posted September 10, 2015 at 12:50 pm | Permalink

              Thanks for your digest of these papers, Aidan.

          • nickswearsky
            Posted September 10, 2015 at 2:05 pm | Permalink

            Pan has long curved fingers,with a relatively short thumb. Many differences occur because chimps use their forelimbs for locomotion. Chimps have strong buttresses of bone and strongly flexed joints that support wrists and fingers as they knuckle walk, which are not seen in humans, allowing for somewhat greater dexterity and flexibility.Chimps do manipulate objects and make simple tools, tho, so their dexterity is pretty good. While these new hominins may have had the anatomy to make tools, there is no evidence they did so.

            • gravelinspector-Aidan
              Posted September 10, 2015 at 6:58 pm | Permalink

              It’s two-way evidence. If they had clubs for hands, then tool use would be inconceivable. But with hands that are not inconsistent with tool use … they may, or may not, have used tools. On the skeletal evidence, one can’t tell.

              • GBJames
                Posted September 11, 2015 at 7:16 am | Permalink

                On might tell, if the bones had cut marks from having been processed with stone tools.

              • gravelinspector-Aidan
                Posted September 11, 2015 at 2:57 pm | Permalink

                They’ve looked. The cut marks they see are 0.1 to 0.3 mm long and match with various gasteropod radulas and “beetle” jaws (I think they’re not entomologists themselves).
                The surface erosion is consistent with common cave fauna. Cave biology is a significant field of study.

              • GBJames
                Posted September 11, 2015 at 3:52 pm | Permalink

                Oh, I’m sure they have. I was just making the general point that one can tell that bones were processed with tools when cut marks are left. If there are no cut marks, then you can’t tell one way or ‘tother.

              • gravelinspector-Aidan
                Posted September 11, 2015 at 7:12 pm | Permalink

                Hmmm, de-fleshed bone weathers differently to flesh-coated bone, IIRC. More “Body Farm” stuff, as well as studying how to make natural mummies and other archaeological groundwork.
                You know the Aggasiz story about you see more by looking harder? It could have been written for examining fossils.
                Actually, it was written for fossil bones – fish bones in the version I heard.

        • gravelinspector-Aidan
          Posted September 10, 2015 at 3:41 pm | Permalink

          Sigh – the bird bones were “out of context”, along with some other bones. They’re attributed to an “unknown previous caver”.
          That WON’T even slow down the speculation predicted above. If you look at the time stamps of my posts in this thread, you can see how long it takes to LIGHTLY read work like this. Speculators don’t need to waste so much time, because speculation is so much more fun than dealing with evidence.
          Where’s my cricket bat? Pour educare les autres.

          • gravelinspector-Aidan
            Posted September 10, 2015 at 3:47 pm | Permalink

            I just thought a few seconds more on the bird bones. Someone took two (chicken) legs (thigh and drumstick) for lunch. More “Doh” ; I’m not switching thought modes fast enough. Is my layman’s interpretation consistent with the HOURS of work that went into addressing this question in the paper :

            The avian bones (UW 101-40 a–f;
            Aves gen. et sp. indet.) represent lower limb elements (including femur, tibiotarsus and tarsometatarsus) consistent with coming from a single individual. The avian specimens were part of a group of bones that had been ‘arranged’ on rocks by an unknown caver prior to discovery by our caving team ( Figure 6B ), and are taphonomically distinct from the hominin assemblage. They lack surface modification and stain patterns, and are characterised by the adhesion of a thin film of calcite crystals over much of the surface of the bone, suggesting they were deposited more recently.

        • Mark Sturtevant
          Posted September 10, 2015 at 3:57 pm | Permalink

          Thank you for the info. I bet a pint of Guinness that these are a variety of the very variable H. erectus. Interesting thing about the slightly curved fingers, though.

          • gravelinspector-Aidan
            Posted September 10, 2015 at 7:01 pm | Permalink

            Even more interesting if we had better evidence as to the shape of “Homo erectus” fingers.
            the absence of comparison suggests that they can’t find evidence either way.

            • nickswearsky
              Posted September 11, 2015 at 8:29 am | Permalink

              I agree with Mark S. I read the differential diagnosis and the distinction between these fossils and, say Dmanisi, seems weakest. Could be an odd or relic populations. South Africa is a bit of a cul de sac, and populations knocking around there may be a bit different from regions where there is more gene flow.

              • gravelinspector-Aidan
                Posted September 11, 2015 at 2:59 pm | Permalink

                OTOH, having at least 15 skeletons from a restricted local population is likely to change the whole statistics of “erectus” just by dint of the number of specimens.

    • gravelinspector-Aidan
      Posted September 10, 2015 at 2:05 pm | Permalink

      Doh!
      They state the bloody obvious, but I missed it’s importance while looking at the “bones” paper.
      The bones were deposited in the permanently dark region of the cave system. So, dating wise, that’s thermoluminescence out of the window (and I’m not sure how well that works on silt- to clay- sized quartz grains in any case – it needs the accumulation of crystalline strain from environmental radioactivity in the bulk of a crystal. So there is likely to be a grain-size effect in the signal). There’s another luminescence effect whose name escapes me .. OSL – Optically Stimulated Luminescence ? Yeah, that’s the puppy. Needs exposure to light to stop. Out of the window.
      Bye bye to the cosmic ray techniques too. Great for granite boulders melting out of glaciers, or granite boulders buried in stone circles. In the dark of a cave, no go.
      And I’m not even out of the abstracts yet. U-Th series, perhaps? That likes speleothems. I know it works to a couple of 10^5 of years, but I’d have to revise my isotope geochemistry to say if it goes deeper.

      • nickswearsky
        Posted September 10, 2015 at 2:09 pm | Permalink

        I thought U-TH might be applicable here. I’m curious as to whether it is being used. The press accounts seem to indicate they really don’t have any idea whether the fossils are millions years old or much younger — perhaps only hundreds of thousands of years old. Perhaps an early hominin that persisted in South Africa long after more advanced hominins were running about?

        • gravelinspector-Aidan
          Posted September 10, 2015 at 3:37 pm | Permalink

          (Still reading)
          Uranium is good, in level. BUT, many of the specimens and the host rock carries rather variable levels of Pb (variable in both quantity and isotopic composition). The fractures that dominate control of the cave structures are sometimes represented by mineralised “stockworks” of very-fine veins.
          There is surface evidence of past mining (and possibly historical data too – I’m still reading) though no mention of what for. With several billion years of available “nearby” geology, and variable amounts of Pb contamination, I’m far less surprised that they haven’t been trumpeting a date from U-Pb, or U-Th series.
          TL;DR version : they’ve clearly looked at this technique, and it doesn’t look like they have got reliable data, and have investigated why.

          • nickswearsky
            Posted September 10, 2015 at 4:26 pm | Permalink

            Very interesting, thanks. With no fossils of other animals, biostratigraphy is also out of the question. This may be a site that is nearly impossible to date with any confidence!

            • gravelinspector-Aidan
              Posted September 10, 2015 at 7:11 pm | Permalink

              Six bird fossils (someone’s recent lunch? see above.) and a scatter of rodent fossils, not closely associated with the hominin fossils.
              I’d look much more closely at the stal, but given the variety of possible sources and isotopic variabilty … that’s not good for getting a date better than a few billion years.

      • gravelinspector-Aidan
        Posted September 10, 2015 at 2:23 pm | Permalink

        The only identified access point into the Dinaledi Chamber involves an exposed, ∼15 m climb from the bottom of a large ante-chamber (the Dragon’s Back Chamber), up the side of a sharp-edged dolomite block that has dislodged from the roof (the Dragon’s Back). From the top of the Dragon’s Back, the Dinaledi Chamber is accessed via a narrow, northeast-oriented vertical fissure, and involves a ∼12 m vertical climb down, with squeezes as tight as ∼20 cm, to reach the floor

        I had been asking myself questions about the roof stability. That answers them – there’s a chert top bed that defines the vertical limit of the cave development, and obviously, if some of the dolomite has that nasty, corrosive water eat away at the bottom, house-sized blocks detach.
        20cm, 7.9 inches isn’t a world record squeeze, but it’s a very, very committing move when you’re going down. Getting back up may be a “not good” experience. And chert is not known for giving a good footing to rock anchors, so if you’re in the squeeze, you may be very seriously on your own. I think my pelvis would draw blood in both directions, and probably my ears too.
        I noticed in the NatGeo footage on the Tv that people were still wearing their helmets when being filmed. In a 20cm vertical squeeze, you’d unstrap your helmet, to avoid being strangled by it. I can see why they needed the “undernourished dwarf” team, to travel this route on a day-to-day working trip.
        As an old joke (a VERY sour one) goes, “the cave imposes it’s own access regulations”.

        • Mark Sturtevant
          Posted September 10, 2015 at 4:01 pm | Permalink

          That seems so incredibly dangerous. Why not bore out a larger passage?

          • gravelinspector-Aidan
            Posted September 10, 2015 at 7:04 pm | Permalink

            Have you ever tried tunnelling rock by hand? I’ve only done moving of “spoil” (the results of PowerGel, a.k.a. “Dr Nobel’s Linctus”). That is tonnes of work too.
            I remain unconvinced of the absence of an easier hominid passage, but their sedimentology argues strongly against a route that could be traversed by sediment.
            Or rats.

            • Mark Sturtevant
              Posted September 10, 2015 at 10:21 pm | Permalink

              I don’t mean the early humans doing the tunneling, but rather that the paleontologists. There are machines that can be brought into the field to help.

              • gravelinspector-Aidan
                Posted September 11, 2015 at 2:41 pm | Permalink

                There is no shortage of such machines.
                By coincidence I got a mail last night from a member of the caving club involved in the discovery. They’re very proud of their involvement in this important discovery in a cave system they discovered, explored and surveyed.
                If, after such a volunteering of information, the scientists were to violate (in the sense of “rape”) the ethics of caving by dynamiting a tunnel into the chamber, then that would probably be the end of cooperation between cavers and scientists for a generation or two. and as both a caver and a scientist, I’d side with the cavers and respect the local rules ; if the locals say “no scientists”, then that would be it.
                Yes, we do, occasionally, use explosives and other technology to make our way into systems we’re exploring. But only after a lot of consideration. Years.
                You may be familiar with an essay in the mountaineering press “Games Climbers Play” (it was the lead article in an essay collection of the same title which has been in press for 35+ years now – pretty popular reading). The essayist’s analysis of mountaineering “games” is relevant to cavers too (there is a lot of overlap between the groups) : we don’t want to make it too easy. That would be wrong and morally offensive.
                From the description, this cave is already easy enough of access. The number of people (between discovery party, the chicken lunch guy, and the science team) who have got there might even exceed the number of people who have walked on the Moon. So blasting a tunnel would be the wrong thing to do. Searching, strenuously, for an alternative entry route is the Right Thing to do. There is glory in that route, not infamy.
                Caving ethics aside, there’s a high chance that the administrivia of dynamiting in the “Cradle of Humanity” UNESCO World Heritage site might take a few decades to organise. The risk assessments alone over “would explosives bring the roof down and destroy the remaining fossils” (the site is about half-excavated), would take years.
                There is adequate access to the site. Palaeontologists who want to visit can get there. They may need to lose 30 kilos, have their femurs shortened, and return to levels of fitness they haven’t had since their twenties, but if they don’t want to do that, then they don’t really want to go.

              • Posted September 11, 2015 at 2:52 pm | Permalink

                Searching, strenuously, for an alternative entry route is the Right Thing to do.

                I must be clueless…I’d think that an alternative entry would be fairly obvious…? I mean, you’ve made it to the chamber with all the bones. Do you see any other holes? Yes? See where they lead. No? There’s no other way in.

                …so…what’m’I missing?

                b&

              • gravelinspector-Aidan
                Posted September 11, 2015 at 3:11 pm | Permalink

                Which is precisely what they have done. Which is why the science crew are using the easy entrance, instead of the “Superman Crawl”. Names like that tell of horrors. By troglodyte standards, horrors. Understatement is (one of) the name(s) of the game(s).
                There is an exit route reported : “the floor drains” – they may well have acquired cemented debris over the millennia.
                There may be a “2-people-abrest, on bicycles” passage up in the roof level – where the roof has since collapsed flat. These things do happen.
                They claim to have searched the site thoroughly for alternative entrances, and I’m sure they have. Caving history is FULL of little holes on “trade routes” (well explored routes with thousands of “tourists” going past every year) which someone squeezed a head into, pushed a few rocks by hand, and discovered “Caverns Measureless to Man”. I’m thinking of a particular place which my club keeps secret, precisely because it is on a trade route. The info is recorded in the CRO (Cave Rescue Organisation) “dead file”, so that in the event of a serious “need to know”, it can be retrieved at need. But by the time the CRO are involved, club members would be involved already, so [meh].
                My bet is – there was another route in. That it hasn’t been found, yet, is nothing unusual.
                I’ll see what the TransVaal Troglodytes (or whatever they call themselves) have to say.

              • Posted September 11, 2015 at 3:21 pm | Permalink

                Something else just occurred to me.

                And you, with your day job, would be the most likely person to know.

                Don’t we have all sorts of gewgaws these days that can “see” beneath the ground? Ground-penetrating radar, sophisticated echolocation mapping, IR goggles that can reveal air currents, that sort of thing?

                How much of that technology is real; how much actually works; how much is affordable to the sorts of people who crawl through caves; how much is portable and can survive the dust and what-not; and so on?

                …and…drones of all varieties, both flying and wheeled, or even simple cameras mounted at the tip of a long bendable shaft like what’s used for medical imaging….

                b&

              • gravelinspector-Aidan
                Posted September 11, 2015 at 7:08 pm | Permalink

                GPR- I spent a week hauling those around in Gaping Ghyll in about 2002. Could penetrate up to about 20m in limestone. Would be lower in higher porosity (more water in the rock.
                Echo sounding – Attenuation increases with frequency ; minimum feature size decreases with frequency. Unfortunately for limestone strong enough to have human size holes, you can’t “see” more than a few tens of metres.
                Thermal tracking? Hmmmm, not hard of it being used technologically, but “following the draft” is a venerable exploration technique. It goes back to the days of caving by candlelight.
                There are people who have worked on this sort of thing for decades. Groups like the Cave Electronics Research Group – whose biggest success is the various generations of “Molephone”, which use magnetic fields to link surface and underground coils. With the two inductively linked, you can communicate voice and data up to a few kilohertz. Go to higher frequencies and the attenuation gets you again, as for GPR. Molephones are also very sensitive to alignment of the coils, which gives you position-finding almost for free. ONCE someone has got the underground antenna into place. It has saved many people’s lives in rescues too.
                Making things “cave shaped” and making the electronics able to survive being dragged through mud, dropped onto rocks, bashed and battered … experience is that after 100mph car crashes, the caving equipment survives unscathed. Better than the car or the driver.
                GPR radar coils are not very “cave shaped.”
                Drones … popular experimental trope these days. The mortality rate (for the drones) is high, interpreting the data is hard, the necessary lighting sucks your flight batteries … and people are working to optimise their use. A dedicated trip with a drone can be easier than a couple of years “maypoling” to explore the top of a hundred metre vertical shaft which you’ve entered at the bottom. Particularly if you get to the bottom after a kilometre or so of diving. (My friend JNC climbed the first 100m of Titan Shaft like this over about 5 years work from the back end of the Peak-Speedwell system, then got enough space to set up a Molephone, got the surface location and managed to dig into the top of the shaft system for a total height of 141m. Until the top entrance was dug out, the top of Titan was a 1/2-lunar location : twice as many people had walked on the Moon as had been to the top of Titan.
                Cameras on sticks – we call it “Maypoling”. Ever tried steering a 4m long pole through a passage that 2m tall people can’t get through? Of limited utility, but it does get used.
                We try. Physics doesn’t make cave exploration simple.

              • Posted September 11, 2015 at 9:39 pm | Permalink

                Thanks for the insight into the current state of the art. Sounds like a lot of technology being put to good use…and infinite room for improvement, as always.

                Might be worth seeing if you can get any of your colleagues to recruit some of the kids at the MIT robotics lab and similar places (if that’s not already been done). Some of the press releases that come from there seem like they’re tailor made for y’all, in retrospect. I bet you’d find some kids who would get really excited about caving in general, and they’d all instantly recognize it as the perfect environment to beat the shit out of their inventions so as to refine them that much faster.

                b&

              • gravelinspector-Aidan
                Posted September 12, 2015 at 4:38 am | Permalink

                Might be worth seeing if you can get any of your colleagues to recruit some of the kids at the MIT robotics lab and similar places (if that’s not already been done).

                What, you mean using robotic autonomous ROVs to do the initial exploration of sumps. It does gete tried, but the effort involved is not that much less than getting a diver to the dive base (they’re self-propelled) with his 30 – 50 kilos of kit. And the human is still more flexible by far – dealing with line tangles or debris in the water is a routine from dive #1 for the acolyte. (Normal practice is to turn a caver into a diver, not turn a diver into a caver. The former route has a higher success rate and far lower drop out and mortality rates.) If you’ve a nice limpid unexplored pool 30 ft from a road, then an ROV may be a successful strategy. The last such in Yorkshire was first dived in the early 1950s using ex-submarine escape sets modified with oxygen (not air!) tanks from crashed bombers. Since then, even an easy-to-access site needs several hours of full-on caving to get to the water line. In Australia there’s a lovely dive site on the Nullabor Plain which would be ideal. But the ROV would have to dive the first 4 or 5 km, climb out of the water and over a 20m tall rubble pile, and then can start the second dive for about 3km to get to the “exploration face”. Sure, it wouldn’t need decompression time on the way out and back like human divers, but a 16km working range is 50 or so times the working range of current models. (There are ocean-going autonomous ROVs with longer ranges ; these are less flexible than divers, being stuffed with batteries.)
                We look at these things all the time, with greedy, avaricious eyes. But very frequently the state of robotics is far behind the state of humanics, particularly in fault tolerance, and pursuing the robotic option isn’t an effective use of resources.
                Like I said, drones are a popular area of research and experimentation.
                For “beating the inventions” to get the bugs out … the analogy I posted earlier of a 100mph car crash causing only cosmetic damage to caving equipment was based on actual events (CUCC going out to Austria, in particular ; on, then above, then flying across, an autobahn). So to survive getting to the start-of-exploration, the prototype has to already be pretty robust. Which also means essentially “feature complete”. Caving bods do work at design stages to help define the operating envelopes, but that’s a long way before prototype building. For example, in the 1980s multi-kilometre dives into Florida’s cave systems, with divers accumulating 10s of hours of decompression time, the divers ended up working with Bill (Bob?) Stone from NASA’s space suit design department to define, build and field test new gas mix control systems which are now the core of the explosion (billion dollar industry? Possibly.) in “recreational rebreather” diving around the world – and fed back a lot of valuable design to NASA.

              • Posted September 12, 2015 at 1:49 pm | Permalink

                What, you mean using robotic autonomous ROVs to do the initial exploration of sumps.

                Hmpf — hadn’t even thought of swimming robots. I was thinking more of something like this:

                https://news.mit.edu/2014/snakelike-robotic-arm-0915

                …or maybe this:

                http://people.csail.mit.edu/jamesm/swarm.php

                But thanks again for more insight into the kinds of insanity y’all push through. Crazy…but, in addition to whatever payoffs you get from doing it, the rest of us at least get to learn stuff about our ancient aunts and uncles that we never would have had a clue about. And recreational rebreathers, and….

                b&

              • gravelinspector-Aidan
                Posted September 12, 2015 at 4:24 pm | Permalink

                Hmmm, the snake-bots. Interesting. Problem is that at this stage of the design, they seem to get power (and possibly off-board computing) from an umbilical. Umbilicals are bad news in confined spaces – the friction does horrible things to your mobility.
                Recreational rebreathers are probably the biggest thing in recreational diving since TriMix. Even my relatively small local diving club has at least two members who dive on rebreathers.

              • Posted September 12, 2015 at 5:28 pm | Permalink

                Not just the snakebots…they’ve got an entire lab of kids (and faculty) working on nothing but inventive robotics. That’s why I’m thinking it might be a good idea to get some of them excited about the stuff you’re excited about….

                b&

              • GBJames
                Posted September 11, 2015 at 4:00 pm | Permalink

                Ground penetrating radar is very real. Here is a very cool recent example of it’s use.

                Here’s another cool example of remote sensing.

                But, of course, this doesn’t apply in all contexts and for all types of deposits. This would be useless, probably, in a cave like the one we’re discussing.

        • Diane G.
          Posted September 11, 2015 at 1:10 am | Permalink

          “20cm, 7.9 inches”

          That gives me terminal claustrophobia just reading about it!

          Stupid question–what possessed them to investigate this fissure in the first place? I.e., did something make them suspect there was this motherlode of bones waiting for them?

          • Torbjörn Larsson
            Posted September 11, 2015 at 5:40 am | Permalink

            The find was by a pair of experienced (professional?) cavers, see their “Rising Star” blog. I assume cavers look for any extension/mapping possibility they find.

          • gravelinspector-Aidan
            Posted September 11, 2015 at 2:47 pm | Permalink

            No, it was just normal cave exploration. Stephen (my .ZA correspondant) didn’t indicate they were doing anything other than having a fun weekend underground, and very happy to have found some unexplored cave. Then “bones!” – and fame for all! Helluva weekend.
            (I’ll have to find out what their names are. I’ve just asked the TransVaal club if they’ve got anything written up already.)

            • gravelinspector-Aidan
              Posted September 12, 2015 at 10:18 am | Permalink

              I corresponded. It seems that NatGeo have a non-discussion agreement with the cavers involved. There were probably comments and blogs at the time of discovery, but NatGeo are now managing the information flow like the corporate media entity that they are.
              Incidentally, it appears that NatGeo have just been taken over by the Murdoch Empire of Evil. Doesn’t bode well.

              • Diane G.
                Posted September 15, 2015 at 4:04 pm | Permalink

                Less than an hour after reading that I run across this cartoon:

                http://www.gocomics.com/tomtoles/2015/09/15

              • gravelinspector-Aidan
                Posted September 19, 2015 at 10:09 am | Permalink

                Depressed snigger.
                At least the NatGeo has a long tradition of bare titties on page 3. That’ll be back, and stronger.

            • Diane G.
              Posted September 15, 2015 at 5:46 am | Permalink

              Wow, that is just so cool!! The discovery, I mean. The NatGeo business is a bit chilling.

              • gravelinspector-Aidan
                Posted September 19, 2015 at 10:07 am | Permalink

                In other news, they’re looking for soot marks on the ceilings, to try to demonstrate the access route.

              • Posted September 19, 2015 at 2:20 pm | Permalink

                Woo-hoo! Somebody owes me a beer….

                b&

            • Torbjörn Larsson
              Posted September 22, 2015 at 7:19 am | Permalink

              This is odd. I watched the NOVA (now PBS) movie, and it seemed to now claim a concerted effort. I.e. these two cavers were acting under the direction of an employee of Berger.

              Maybe I misunderstood.

              • gravelinspector-Aidan
                Posted September 22, 2015 at 7:57 am | Permalink

                From what I hear, the initial discovery was simply a normal “pushing” trip by people from the TransVaal caving club. When they found the bones, they recognized their potential significance, did their surveying work (which can be no more than a sketch), looked for further ways on, then backed out and brought the finds (including several bones that they brought out from the surface exposures) out. Then they contacted Prof Berger (who was known to them for other work in the area) … and the circus begins.
                I believe that Prof Berger did then arrange for a return visit with cameras, and probably surveying kit, and started looking for funding and troglodyte archaeologists. So were probably talking about the same sequence of events, but with different stresses being put on different phases.

  16. ThyroidPlanet
    Posted September 10, 2015 at 11:08 am | Permalink

    “Modern chimpanzees – our closest living relatives”

    Wikipedia says bonobos and chimps can be referred to both as chimpanzees – which is closest to Homo sapiens – pan troglodytes or pan paniscus? This is a loose end I’ve been dragging around for a while.

    • Posted September 10, 2015 at 11:16 am | Permalink

      Bonobos and chimps are equally closely related to us. Neither one is closer than the other.

      Our common ancestor with them produced a lineage that split to produce (among other things) both modern chimp species.

      • ThyroidPlanet
        Posted September 10, 2015 at 11:20 am | Permalink

        Thanks – with the vanishing attention I had in the past few minutes, I can see there is some argument about how close – “equal” is good enough for me.

        • Posted September 10, 2015 at 11:55 am | Permalink

          What might help…imagine Alice has two sons, Bob and Charlie. Bob has a son and a daughter, David and Eve. Is Charlie more closely related to David or to Eve? Now, just to muddy the waters, imagine timing the sequence of events such that Charlie is younger than both David and Eve. Would that change your answer?

          b&

    • GBJames
      Posted September 10, 2015 at 11:17 am | Permalink

      Presumably they are equally close to us, both having descended from the same common ancestor after the Pan split with Homo. I think the error is to think of one of those having been ancestral to the other.

    • Posted September 10, 2015 at 11:18 am | Permalink

      I think it is generally believed that the bonobos and chimpanzee species diverged after the split with us. Thus, they are roughly equally closely related to us.

      According to http://www.timetree.org, the split took place about 2.8 million years ago, as opposed to about 6.6 million years ago for the Homo – Pan split.

    • Posted September 10, 2015 at 11:47 am | Permalink

      I lumped bonobos and “regular” chimps together as “chimpanzees” there. But I probably should have said “bonobos and chimps”

      • Matt G
        Posted September 10, 2015 at 11:51 am | Permalink

        Or simply as Pan, since bonobos and common chimps are Pan paniscus and Pan troglodytes respectively.

      • ThyroidPlanet
        Posted September 10, 2015 at 11:57 am | Permalink

        Thank you sir!

    • Mark Sturtevant
      Posted September 10, 2015 at 3:49 pm | Permalink

      It is pretty common shorthand to just refer to chimpanzees when one is comparing the two species with humans or other species. I see no problem with it.

      • John Scanlon, FCD
        Posted September 11, 2015 at 10:16 am | Permalink

        Increasingly these days, it is misleading to use ‘common’ as part of the common name of any animal. Chimpanzees are not common, any more than bonobos are pygmies (or humans uniformly wise), so it’s lucky we have other ways of referring to them.

  17. Posted September 10, 2015 at 11:14 am | Permalink

    As a (plant) taxonomist, I can’t be upset at the researchers for giving Homo neladi a name at this point.

    The fossils have a combination of traits a little different from all the other named taxa. So either the researchers have to stretch the definition of one of the other names, or give these their own. It may not be clear which other group should be “stretched” to include these fossils.

    Naming species is fun, and I can’t begrudge the researchers this experience after all the work they’ve done. And future researchers will have to take this name into consideration, even if it ends up lumped.

    Taxonomy in general and very definitely hominin taxonomy goes through cycles of splitting and lumping. Hominin taxonomy is in a splitting phase now. Give it a few more decades, with more fossils that give a better understanding of intraspecific variation in the groups, and major lumping will occur, as has started with the Dmanisi fossils.

  18. Posted September 10, 2015 at 11:14 am | Permalink

    I love these articles. It’s like the shape of biological history is a giant puzzle and we’ve just got hints and pieces here and there, and many unfinished spots we can’t really connect to the borders yet.

    We are but brothers and sisters in an ever-growing family tree 🙂

  19. Posted September 10, 2015 at 11:19 am | Permalink

    I hope they can somehow extract some DNA from a molar or two. I wonder what the preservation of organic matter in these teeth is like? If buried in some mud, it could be good…

    • Torbjörn Larsson
      Posted September 10, 2015 at 11:35 am | Permalink

      These fossils could be 3 Myrs old, from a warm and often humid cave. Oldest DNA sequenced is ~0.4 Myrs, IIRC.

      • gravelinspector-Aidan
        Posted September 10, 2015 at 12:43 pm | Permalink

        Human DNA, from Sima de los Huesos (Atapuerca, Spain) ; they cite the work, but not the DNA work. One would hope. But taking apart a molar to look for DNA is destructive. If they’ve got any sense (a pretty safe bet!), then some of the “best” teeth are being kept in a freezer, pending future work or techniques from (say) Paabo’s lab.
        When you see Paabo giving DNA analyses of pigs or bovines from 3/4 of the (not yet established) age of these fossils, then the option of sacrificing some of this irreplacable material becomes a matter for discussion.

        Oh, a couple of other papers, if anyone has “nature comms”. On on the hand, and this one on the foot : “The foot of Homo naledi”
        WEH Harcourt-Smith, Z Throckmorton, KA Congdon, B Zipfel, AS Deane, MSM Drapeau, SE Churchill, LR Berger, JM DeSilva
        Nature Communications, 6, 8432, 2015
        http://dx.doi.org/10.1038/ncomms9432

        • Torbjörn Larsson
          Posted September 11, 2015 at 5:42 am | Permalink

          Agreed, they should try.

          • gravelinspector-Aidan
            Posted September 11, 2015 at 2:51 pm | Permalink

            … when there is a reasonable chance of success.
            The material is literally irreplaceable. The testing is destructive. Moon rocks for comparison are relatively easy to replace – send people back there. All it takes is money and hardware. There may be precisely big-fat-zero other material in the universe from this species.
            Archaeology is conservative in it’s techniques if at all possible. You may never get another specimen like that one.

            • Posted September 11, 2015 at 2:58 pm | Permalink

              …especially considering that there’s a reasonably high probability that, in no more than several generations, there’ll be nondestructive ways of getting these answers. Or, at least, much less destructive…consider how much radiocarbon dating has advanced over the years, to the point that you now need very delicate tweezers to handle the amount of sample required. Who’s to say that, in half a century or less or more, there won’t be a way to drill with something far finer than an human hair into the precise optimal location and the material removed in the drilling would be sufficient for DNA extraction? Or, much more likely, for some sort of imaging technique that’ll reveal that there’s no chance of anything there to recover, so no point in trying.

              b&

              • gravelinspector-Aidan
                Posted September 11, 2015 at 3:12 pm | Permalink

                Improving techniques is another argument for conservatism about destroying samples.
                Make haste, slowly!

  20. EvolvedDutchie
    Posted September 10, 2015 at 11:23 am | Permalink

    The important question is: did they have souls?

    Joking aside, this is a very interesting find. It’s also good to read a critical note on the press coverage.

  21. Torbjörn Larsson
    Posted September 10, 2015 at 11:33 am | Permalink

    I suspected that something was afoot since Hawks (2nd author) hadn’t blogged for a couple of weeks!

    That they did catch so many individuals is amazing. Also, they have half the variation spread of other groups found, but that could be a selection effect of a clan that knew of the crevice and its dead drop. It would support the hypothesis of a ritual behavior, I think.

    It is most likely from a pauper period of the hominin, an especially Homo, record. While its mosaic traits further undercut the idea of using a single specimen as indicator of trends, they do remind of the Australopith and Homo mix of the recent Ledi jaw. The latter is ~ 3 Myrs old. These finds join a lot of recent finds such as tools and cutmarks, from that period. [ http://arstechnica.com/science/2015/09/humans-arent-so-special-after-all-the-fuzzy-evolutionary-boundaries-of-homo-sapiens/ ; http://arstechnica.com/science/2015/09/over-a-dozen-skeletons-of-an-unknown-early-homo-species-found/ ]

    So, a flurry of articles, so I can’t remember here I read this but Tim White is as usual cautious. He notes, unless I misremember and/or misrepresent, that everything seen could be an early Erectus. (I haven’t read the papers, but I think the brain size has an overlap with a H. erectus individual.) I didn’t know this until yesterday, from the above articles, but already 2009 he mushed a lot of species together (but not H. floresiensis and H. erectus!) , cf Jerry’s image:

    Tim White’s representation of the human family “cactus,” showing what (in 2009) he considered to be well-established species living at any one point. Names in grey are considered to be synonyms for already-established species.

    [ Ars Technica; Tim D. White, Cold Spring Harbor Symposia on Quantitative Biology ]

    • Torbjörn Larsson
      Posted September 10, 2015 at 11:41 am | Permalink

      Lots of typos and html-os.

      The “cactus” reference goes towards that a cut of the three looks more like it than the usual label of “bush”. (Could be especially mentioned if White is a lumper, but seems a good notion anyway.)

    • Torbjörn Larsson
      Posted September 22, 2015 at 7:25 am | Permalink

      I’ll amend this, it seems White hasn’t followed his own precept of not commenting until having seen the original fossils.

      “Even White, who has famously written (White 2000) that no one should publish on a fossil without seeing the original, has twice this year chased attention for his own fringe views about new species.”

      [ http://johnhawks.net/weblog/fossils/naledi/homo-naledi-homo-erectus-2015.html ]

  22. eric
    Posted September 10, 2015 at 11:41 am | Permalink

    Thanks for the science article Jerry!

    The species debate is as old as Darwin; he brought up the issue in OOS (IIRC, using flowers as his example of ‘one man’s variation is another man’s species’).

    What I find most interesting is the location; SA is a long way from Tanzania. This essentially means that australopithicenes could have been all over Africa, and maybe even in the middle east or further.

    • gravelinspector-Aidan
      Posted September 12, 2015 at 10:26 am | Permalink

      What I find most interesting is the location; SA is a long way from Tanzania. This essentially means that australopithicenes could have been all over Africa, and maybe even in the middle east or further.

      For over a decade now, there has been increasing amounts of work (and results of that work) in .ZA in general, and particularly in this “Cradle of Humanities” area.
      Hominins have been found up to 5-plus Myr ago from East, South, and Saharan Africa ; it’s pretty much a waiting game over when confusing hominins are found from the Congo area, Angola and west Africa. Though the general moistness isn’t confidence inspiring. It it wasn’t for local security issues, I’d think Angola would be getting a lot more attention.

  23. Posted September 10, 2015 at 11:45 am | Permalink

    Nifty. This is certainly complicating our family tree!

  24. BobTerrace
    Posted September 10, 2015 at 11:48 am | Permalink

    Re-subscribe after fat fingered deletion

    • John Scanlon, FCD
      Posted September 11, 2015 at 10:19 am | Permalink

      Just blame your apical tufts.

  25. Mark R.
    Posted September 10, 2015 at 11:58 am | Permalink

    The announcement was made at the Maropeng Centre at the Cradle of Humankind by leading paleoanthropologist professor Lee Berger.

    “I’m pleased to introduce you to a new species of human ancestor. The new species within our very own genus – a species we’ve called Homo naledi. Naledi, meaning star.”

    Obviously Berger is quite convinced that this is a ‘new species within our very own genus’. So based on this quote, I can see why the journalists created that headline…plus to add intrigue, of course. I am surprised at Berger’s presumption…as a paleonathropologist professor, you’d think he’d be a little more cautious in describing this find as a direct ancestor. And I wonder if naledi meaning ‘star’ is connoting fame…if so, I think it’s a little bombastic.

    • Posted September 10, 2015 at 12:15 pm | Permalink

      Yes, that “ancestor” remark is deeply misguided. But science journalists should know at least enough to question that. Carl Zimmer certainly would!

      • Posted September 10, 2015 at 12:19 pm | Permalink

        Faye Flam, too — and I just realized I haven’t heard from her in ages….

        b&

    • barn owl
      Posted September 10, 2015 at 12:50 pm | Permalink

      I think “star” comes from the local name of the cave in which the skeletons were found.

      • Mark R.
        Posted September 10, 2015 at 12:55 pm | Permalink

        Thanks for the clarification, ‘star’ as the name of the locale makes more sense.

    • gravelinspector-Aidan
      Posted September 10, 2015 at 1:19 pm | Permalink

      And I wonder if naledi meaning ‘star’ is connoting fame…

      The discovery chamber is in a complex of caves which has been known as “Rising Star” for years ; the specific name is from a South African language translation of “Star.”
      Cavers don’t normally report the etymology for their names.

  26. Josh
    Posted September 10, 2015 at 12:52 pm | Permalink

    Might there be the possibility that they secreted their dead in such a difficult place to get to, to hide from predation?
    A number of different species have many behaviors to hide their whereabouts. Chickadees, when hollowing out a hole in a tree, will spend much energy carrying mouthfuls of sawdust away from the tree to hide their location from potential predators (I have taken a cute photograph of just such a behavior).
    Having carrion lying about close by or shallowly buried would tend to invite large carnivores (feline as well as canine).
    I have only heard people speaking of this as being an example of humans ceremoniously dealing with their dead, but I can’t help but think that if I were an ancient humanoid species (without firearms) in Africa that I would not want to leave “cat food” out in the yard while I slept nearby.

    Josh Lincoln

    • GBJames
      Posted September 10, 2015 at 12:59 pm | Permalink

      I think you mean “from scavengers” rather than “from predation”.

      We’re not talking about settled communities here and it would be normal to move around from site to site while hunting and gathering food. Scavengers could probably find a cave entrance as easily as they could dig up a buried body. In any case, nobody wants to hang too long around a dead guy and if there is a cave near to hand, it might be easier to drop a corpse into a cave than to dig a grave. Or maybe not, depending on local conditions.

      • Josh
        Posted September 10, 2015 at 1:37 pm | Permalink

        I actually meant predation. Savaging would be accurately what would happen when the lion/jackal/hyena… ate the corpse, the predation would be what would happen if a pride was attracted to a corpse and ran out of food and ate a living creature. Trying to prevent this predation would be a possible explanation of squirreling the remains away in a remote difficult to get to location.

    • winewithcats
      Posted September 13, 2015 at 2:56 pm | Permalink

      If your premise is true, then it would imply that they had the knowledge (or at least instinct) to bury their dead in a hole, and the physical capability to take the dead down a deep hole that’s difficult to access; yet, they lacked the knowledge, intellect, instinct, desire, or physical capability (lack of tools) to simply dig a sufficiently deep hole themselves.

  27. Posted September 10, 2015 at 1:00 pm | Permalink

    Thanks very much for your wonderful digest of this paper. I really appreciate it; having little access and less time to things like this, though I find them fascinating.

  28. W.Benson
    Posted September 10, 2015 at 1:04 pm | Permalink

    The feet are more similar to human feet than the figure suggests at first glance. The fossil foot in the photo lacks all the toe bones of digits 2-5.

    Suggesting that “H. naledi” was a climber because the curved finger bones are curved seems premature. It seems possible that bone curvature is a vestigial trait subsequently lost in modern humans. Google Earth shows the cave site now covered with savanna scrub (and scattered eucalypt? groves). The fossils best fit — IMHO — an age of 1 million years.

    H. erectus is reported to have relatively thick cranial bones. What does the article say?

    Perhaps the fossilized creatures were driven deep into the cave and died during a dispute with another group. If it was a burial site, it would tend to hold more older individuals than if it were a social group (with young and juveniles) that somehow became trapped.

    • gravelinspector-Aidan
      Posted September 10, 2015 at 1:23 pm | Permalink

      The feet are more similar to human feet than the figure suggests at first glance. The fossil foot in the photo lacks all the toe bones of digits 2-5.

      Yes, I thought the foot looked strange, which is why I kept my trap shut until I’d read that bit of the paper. Bipedal locomotion, mosaic-ed with a somewhat australopithecine-like skull and dentition. Mosaic evolution.

      • Torbjörn Larsson
        Posted September 10, 2015 at 4:40 pm | Permalink

        As I understand it the best fit to that mosaic is the Ledi jaw. While it is possible with a 1 million year old find, it seems very odd – to a layman – to see the same mosaic (and small brain case) return 2 million years later.

        What would another “best fit” be based on? [Disclaimer: If the hominin fossil record between 2 and 3 million year is sparse, I certainly would hope the fossils originate there…]

        • Posted September 10, 2015 at 6:47 pm | Permalink

          “If it was a burial site, it would tend to hold more older individuals than if it were a social group (with young and juveniles) that somehow became trapped.” Maybe not. Mortality rates among the young are high in non-industrialized areas, and many individuals don’t reach adulthood.

          By the way, one of the individuals in this fossil collect was very old.

        • gravelinspector-Aidan
          Posted September 10, 2015 at 7:15 pm | Permalink

          All of the hominin fossil record is pretty sparse. That is one of the fascinations of a deposit like this. Even if they represent one body per generation, and generations were 20 years, this is still 300 years of events. That is not incredible in the cave deposits context, and vanishingly small in human archaeology.
          It’s an important find, regardless of the detailed results.

  29. kansaskitty
    Posted September 10, 2015 at 1:28 pm | Permalink

    This is fascinating stuff! And yes, science articles on WEIT are read by me, even though I don’t feel qualified to comment. I read to learn.

  30. Michael Scullin
    Posted September 10, 2015 at 1:45 pm | Permalink

    Back when I was a graduate student at the University of Illinois U/C in the late 1960s even a tooth could be named a “new species.” Having had both plant and vertebrate taxonomy, I just avoided physical anthropology for a few years while new hominin discoveries literally poured in in the 1970s and 1980s. Hominin taxonomy more or less got its “house in order.” But I totally agree with Jerry on this. There will some hot and heavy debates over this at the paleo meetings and in their journals. It looks more Australopithecine to me. I’d like to hear what the Leakeys have to say about it for starters. There is great competition between the South African paleos and those who work in Kenya and adjacent areas. Where Naledi fits in is far from settled.

    • gravelinspector-Aidan
      Posted September 12, 2015 at 10:31 am | Permalink

      Where Naledi fits in is far from settled.

      It’s very high in the “good PR” tree. All intramural differences aside, anthropologists and archaeologists are going to be happy bunnies over this.

  31. Curt Nelson
    Posted September 10, 2015 at 2:03 pm | Permalink

    Does anyone know whether the bones are really fossilized? Is there potential DNA?

    • Torbjörn Larsson
      Posted September 10, 2015 at 4:43 pm | Permalink

      If there is DNA that can be sequenced in that climate, the fossils would be _very_ young. That would be interesting too…

      • Curt Nelson
        Posted September 10, 2015 at 5:11 pm | Permalink

        I think caves are special places for DNA preservation because of their even coolness, and dryness – or not. Maybe it’s a wet cave.

        I read somewhere that the bones were free, not encased in rock, so maybe they’re not fossilized (replaced with minerals), and there’s DNA there.

        • Posted September 10, 2015 at 5:19 pm | Permalink

          Even if they weren’t mineralized, DNA doesn’t have a shelf life of millions of years. At least, not that I’m aware of.

          By the time you start measuring time in millions of years, you get all sorts of effects of atoms simply randomly migrating and diffusing, even in substances that we normally take for granted as perfectly inert. For example, if I remember right, pretty much any gas will leak out of a sealed-by-weld metal tank if left for millions of years in vacuum. Yes — those heavy solid canisters designed to safely hold nasty explosive and corrosive gasses…those will leak over these sorts of timespans.

          …not to mention, of course, any rubber or plastic components, seals or valves or bearings or whatever, will long since have outgassed and otherwise disintegrated….

          b&

          • Curt Nelson
            Posted September 10, 2015 at 5:23 pm | Permalink

            Yes. I see that DNA that old hasn’t been sequenced. I was thinking about the Denisovan sequence they got from the finger bone but that must have been much younger.

            • Torbjörn Larsson
              Posted September 11, 2015 at 5:57 am | Permalink

              The Denisovan cave is different in the sense that it doesn’t go over freezing much. Wet at a guess (condensation), but not harmful wet.

              They should definitely try sequencing, as aidan suggests above. I just don’t think they will see much. (But that in itself could push the burial dates back some, as would a C14 dating attempt do.)

              DNA has, despite its greater chemical stability of its backbone, some nasty chemical degrees of freedom.

              – It can flop around more than RNA, so has two more strand configs. (Z helix and, if a G base stretch, a quad config possibility that evolution now uses for chromosome regulation and end protection.)

              – It can base change/racemice.

              – It can base pair erroneously.

              But the largest killer may be prokaryote contamination. [It would be interesting to hear from an expert on the relative weight of the problems.]

              There are methods to filter out the original DNA remnants, but if prokaryotes eats the organics there will be ever less original material left.

        • gravelinspector-Aidan
          Posted September 12, 2015 at 10:45 am | Permalink

          I think caves are special places for DNA preservation because of their even coolness, and dryness – or not. Maybe it’s a wet cave.

          Caves acquire their local average temperature quite rapidly once you get away from entrance drafts. So, British caves are generally 4-5 Centigrade ; the Denisova cave (quite high in Siberian hills) runs pretty close to zero.
          I don’t have figures for these caves, but the gear the cavers was using was for much warmer conditions than Britain. I’d guess well above 10deg C, but probably not 20deg C.
          The presence of multiple levels of flowstone deposition forming ledges on the walls and in side passages speaks to variable water and sediment levels over the millennia. Which is pretty normal – caves are complex environments. There are “drains” reported in the floor through which water drains away. That too suggests potentially quite variable water levels and throughputs.

          • Curt Nelson
            Posted September 12, 2015 at 3:58 pm | Permalink

            That’s very helpful information. Thank you.

  32. @eightyc
    Posted September 10, 2015 at 2:57 pm | Permalink

    Can you use the magnitude of time between two fossils as a demarcation point for what makes one species separate from another?

    In other words,

    Try and attach probabilities to differences in time between fossils.

    • John Scanlon, FCD
      Posted September 11, 2015 at 10:29 am | Permalink

      It doesn’t work very well in practice. The rate of evolution (in morphology, in allele substitution, etc.) varies much over time and between lineages; you can measure pairwise differences and compare them to ‘average’ differences between species of (approximately) known divergence times, but there’s no magical threshold for species. The difference in age of two fossils is a bare minimum measure of their time separation as evolving lineages, because you can (probably) never know if one is ancestral to the other, or their ancestors diverged from each other long before either specimen lived.

    • gravelinspector-Aidan
      Posted September 12, 2015 at 10:47 am | Permalink

      To agree with John, in theory you can do that. And in theory there is no difference between theory and practice. But in practice, there is.

  33. Posted September 10, 2015 at 2:58 pm | Permalink

    Wonderful, although pedestrians like me ponder the complex evolution tree. Love the constant flow of discoveries.

  34. nickswearsky
    Posted September 10, 2015 at 3:31 pm | Permalink

    If I am not mistaken, I believe Berger erred in his publication announcing the new species. He has the new species name in the title of the article at eLife. I was always taught that the rules of taxonomy require the formal designation of a species name must follow the description. So the species name must never appear in the title. THis has happened before, and has given cause to some to propose that certain species names are invalid.

    Any paleontologists or zoologists available to weigh in on this?

    • John Scanlon, FCD
      Posted September 11, 2015 at 10:47 am | Permalink

      Some journals have traditionally insisted on leaving new names out of titles and abstracts (or even introductory paragraphs before you get to the ‘Systematics’ section of the paper), but the reasons for this practice (if not the practice itself) were dead and gone by the mid-1990s. Titles and abstracts used to be sent around to indexing services somewhat in advance of the printed text, so any names in them would be physically available while still technically nomina nuda; prudish editors insisted on such naked nomenclature being kept out of sight until properly clothed in a formal description.

      This is related to the superstition concerning ‘page priority’ in the case of potential synonyms created within a single publication; in fact there never has been such an official rule, and all the Codes of Nomenclature say about nomina nuda is (in effect) “put your clothes on”.

  35. Posted September 10, 2015 at 3:44 pm | Permalink

    For plants, using the name in the title doesn’t seem to be a problem. Whether or not the name is used in the title, it always precedes the description itself in the text. I don’t know if it’s different for animals.

    • nickswearsky
      Posted September 10, 2015 at 4:21 pm | Permalink

      Thanks!

  36. Mark Sturtevant
    Posted September 10, 2015 at 3:47 pm | Permalink

    I have read in the article in Science News (which is, of course, very gushy about the whole thing) that there seems to be more bodies in the cave.

    • gravelinspector-Aidan
      Posted September 12, 2015 at 10:51 am | Permalink

      Less than (by eyeball) half of the surface area of the chamber has been excavated. The presence of other unexcavated specimens would be a “racing certainty” to me.
      I would be surprised if they excavated the rest of the site in the next few decades. Techniques advance all the time, and excavation is the ultimate destruction of the material.

  37. gravelinspector-Aidan
    Posted September 10, 2015 at 4:03 pm | Permalink

    I’ve lost track in the comments of where I am in my reading. so I’ll start a sub-thread. (Incedentally, if anyone wants to slurp the posting times to slap creationists around the head against the charge that “you scientists accept other scientists work without even considering it, I’ve got no objections. ProfCC and WordPress’s copyright rules may object, but I don’t.
    And for people who wonder how long ProfCC spends on his ‘science’ posts, you have an indication. ProfCC’s detailed methods may differ in detail, but I doubt the time scale will differ by much.
    To data ; what’s in my buffer?

    More importantly, in some of the material we observed, regions that conventionally disassociate both early and late in the decomposition process are represented as anatomically aligned and articulated groups, suggesting limited post-mortem spatial alteration and disaggregation within the chamber in both the proximate putrefactive (early) and distal decompositional (late) periods

    (Obviously from the “Geology and Taphonomy” paper) This pretty strongly EXCLUDES the “washed in from a surface hole” range of hypotheses ; if the bones were washed in, the bits that fall apart most easily (hands, feet) would be over-represented.

    • gravelinspector-Aidan
      Posted September 10, 2015 at 4:39 pm | Permalink

      The features observed on the Dinaledi collection were compared to surface modifications produced by 16 invertebrate taxa on bones in controlled experiments

      Do we have any volunteers for “The Body Farm” in the readership. This is probably (it’s not referenced) a link between archaeology and forensic science. (Then again, I’ve never watched an episode of those “crime lab” series. “Quincey” was good enough for me.)

      • Posted September 10, 2015 at 5:12 pm | Permalink

        I’m sure I can think of some suggestions who wouldn’t necessarily be missed. Or even those whose silence would be noticed but welcomed….

        b&

        • gravelinspector-Aidan
          Posted September 10, 2015 at 7:17 pm | Permalink

          I shall blunt down my “blunt instruments”.
          “Yer Onner, he was beaten to death by sarcasm!

    • gravelinspector-Aidan
      Posted September 10, 2015 at 4:54 pm | Permalink

      The distribution of Unit 2 below the current entry shaft into the Dinaledi Chamber, and the orientation of Flowstones 1a–e that cover Unit 2 and slope into the chamber, together strongly suggest that the current entry shaft has always been the main entry point for sediment into the chamber. This also indicates that the fossils of H. naledi entered via this route

      i.e. the current access route.
      I understand their logic … preserved fragments of flowstone-cemented dirt sloping away from the current access route … BUT
      That access route is damned hairy. Even for smaller people, a 12m drop is not to be sniffed at. And vertical squeezes are not nice places, and never will be. I still suspect an unidentified entry point.
      (Sips beer) No, that is still a severe entry route, even without carrying an adult corpse. Not impossible, but a LOT of dangerous, hard work. Digging a 6ft deep hole in the ground, or erecting a chest-high obelisk would be easier.

      • gravelinspector-Aidan
        Posted September 10, 2015 at 4:58 pm | Permalink

        Sorry, missed a point. Many skeletal elements are preserved articulated, but occasional bones are displaced. AND the bone surface erosion shows nothing larger than a snail’s radula. That mix of articulation and disarticulation is, I’m sure, at the core of the evidence for “burial practices”.

      • Posted September 10, 2015 at 5:13 pm | Permalink

        Makes me think even more that they may have been forced to enter, or entered as some sort of cultish ritual.

        b&

        • gravelinspector-Aidan
          Posted September 10, 2015 at 7:22 pm | Permalink

          In tight squeezes, all that external force does is ruck flesh up against the rock. People have died, slowly, learning this. People’s lives have been saved by concreting the body in place instead of trying to retrieve it. After floods, when bits of body have been found, Police sergeants have taken the evidence and buried it, rather than distress the bereaved with a third or fourth inquest.
          Vertical squeezes can be real bastards. Even worse than underwater squeezes.

        • John Scanlon, FCD
          Posted September 11, 2015 at 10:52 am | Permalink

          Trial by snails?

          • gravelinspector-Aidan
            Posted September 12, 2015 at 10:53 am | Permalink

            The radulas of Justice grind fine, but slowly?

    • gravelinspector-Aidan
      Posted September 10, 2015 at 5:08 pm | Permalink

      However, sedimentation patterns indicate that the accumulation of Unit 2 with fossils occurred below the current entry point into the chamber, and alternate routes did not involve vertical access shafts that connected directly to surface in either the Dinaledi Chamber or nearby Dragon’s Back Chamber.

      I’ve never suggested (or thought) a direct route ; just a less difficult route. Caving experience says that where the water flows necessary to form a cave exist, there are normally multiple sources and sinks. We may not know where they are, but that is not the same as non-existence.
      The lack of “green” bone fractures argues against the bodies being dropped in, even after a protacted underground voyage. It’s an unsimple problem.

      • Torbjörn Larsson
        Posted September 11, 2015 at 6:06 am | Permalink

        That is odd, I thought I had read of fracture damage, which is why I assumed they were simply dropped in over the years.

        Now it is “unsimple” indeed. 🙂

        • gravelinspector-Aidan
          Posted September 11, 2015 at 2:53 pm | Permalink

          The water table has varied over the years (look at the stacked flowstone levels in some of the pictures in the “geology” paper) ; that exposes the bones to varying degrees of humidity. So they swell and shrink.
          And we’re back to the Body Farm and experimental human taphonomy.

      • Torbjörn Larsson
        Posted September 11, 2015 at 6:31 am | Permalink

        Also, thanks for all the heavy lifting! (I have deadlines, very inconvenient. :-/)

        • gravelinspector-Aidan
          Posted September 11, 2015 at 2:54 pm | Permalink

          (I have deadlines too. I love the sound they make as they woosh past.)

          • Torbjörn Larsson
            Posted September 22, 2015 at 7:28 am | Permalink

            X-)

    • gravelinspector-Aidan
      Posted September 10, 2015 at 5:16 pm | Permalink

      Someone asked about .. I forget, but I answered about Sima de las Huesos.

      The Dinaledi situation shows similarities with the Sima de los Huesos assemblage in several respects. However, the Dinaledi hominins recovered to date are entirely free of cut marks, tooth marks, or peri-mortem fractures while each of these is present at low frequencies in the Sima de los Huesos sample.

      That is one of the delights of large samples – you can interpret rare occurrences with more confidence.

      • Posted September 10, 2015 at 5:22 pm | Permalink

        So…no obvious signs of violent death, or violence soon before death? Most curious…

        b&

        • Mark Sturtevant
          Posted September 10, 2015 at 5:54 pm | Permalink

          I thought from his earlier posting that there were was a mix of articulated and disarticulated bones, and that could mean they were partially dismembered when put in place.
          What I would like to see is evidence of consistent disarticulation points. Like generally separating the lower leg from the upper leg. People who break up a lot of corpses for easy carry or whatever would probably do it a certain way, over and over. At least I would…
          I think there are similar funerary practices that humans have done recently, where bodies are put into caves post mortem.

          • Posted September 10, 2015 at 6:04 pm | Permalink

            But by how much were they disarticulated, and is there any sign of when?

            I’m thinking that if, for example, one person died whilst sitting or laying on top of a rock, given enough time, an outstretched limb could simply fall off of its own. And if there was any weathering of the rock the person was sitting on, that could move things around even further.

            Over the course of millions of years, even a seemingly perfectly tranquil cave can see all sorts of natural milimeter-by-milimeter upheavals that could shift bones around long after the soft tissues had turned to dust.

            b&

          • GBJames
            Posted September 11, 2015 at 7:11 am | Permalink

            Reburial is a common form of mortuary behavior for humans. And it is rather common for archaeological sites to contain both articulated and disarticulated skeletons. Sometimes it represents different communities behaving differently over time. Sometimes it represents grave reuse. We humans love to mess around with dead bodies in lots of different ways.

            And sometimes critters dig tunnels in the ground and use the bones to for entertainment.

            • gravelinspector-Aidan
              Posted September 12, 2015 at 10:59 am | Permalink

              Sometimes it represents grave reuse.

              Which we still do to this day.

        • gravelinspector-Aidan
          Posted September 10, 2015 at 7:24 pm | Permalink

          It is a VERY curious deposit.
          But the people studying it seem to have thought long and hard on the question. Not that that will protect them from internet trolls.

        • gravelinspector-Aidan
          Posted September 12, 2015 at 10:57 am | Permalink

          So…no obvious signs of violent death, or violence soon before death

          Or violence shortly after death – e.g. being dropped 12m down a hole in the ground (actuallt the cave is some 30m below the present land surface, but the known access route is on the order of 250m long as the caver thrutches. Looking at the geological map, a shortest-possible direct route to surface would still be in the order of 100m of caving. That assumes that the land surface hasn’t been eroded towards the cave since deposition.

  38. Posted September 10, 2015 at 6:19 pm | Permalink

    This would seem to present a major problem with the theology of Original Sin. Under all but the most vague interpretations, Original Sin includes Adam and Eve gaining knowledge of death. In fact, many Sophisticated Theologians even pinpoint this knowledge of eventual bodily death as the metaphor being described in Genesis. The assumption, of course, is that other species do not possess this foreknowledge; likewise, neither did the first humans.

    Given that this species clearly had to understand death in order to have a procedure or ritual following it, this would seem to present a problem with even the metaphorical interpretation. And, if the theologians try to dismiss this by claiming this was a different species who may have understood death but could not assent to understanding of the Creator, by what criteria is this understanding measured? Now even the metaphor of Genesis has been rendered meaningless.

  39. Dale Franzwa
    Posted September 11, 2015 at 12:16 am | Permalink

    Thanks Jerry. I’ve seen the stories on TV news and your comments are so much more insightful.

  40. Posted September 11, 2015 at 4:39 am | Permalink

    Amazing article Jerry! I’m sharing this 🙂
    I love how you first go through all the basics so clearly and succinctly.
    About Homo Sapiens and Neanderthal being the same species, is it not controversial ? I thought our neanderthal genes were most likely coming from some “accidental” fertile hybrids. What i mean by accidental is that they would mate but with no result for 99% of cases. In this case we’d be in a gray area.

    • Torbjörn Larsson
      Posted September 11, 2015 at 6:29 am | Permalink

      Yes, I have seen people be all over the place in this. I thought Jerry would say “different species” or “incipient species”, since the sequencing revealed that species barriers were going up, some sperm incompatibility alleles found. Paleoanthropologist Hawks, one of the authors on the papers, is decidedly not saying “different species”, at least in 2010:

      “Does this mean that Neandertals belong in our species, Homo sapiens?

      Yes.

      Interbreeding with fertile offspring in nature. That’s the biological species concept.

      Now, some paleontologists might still disagree – maintaining that species are units that can be distinguished morphologically, or by one or more derived features, or any number of other definitions. That’s fine with me, as long as they’re clear. But understand: It does define all non-Africans today as an interspecific hybrid population.”

      [ http://johnhawks.net/weblog/reviews/neandertals/neandertal_dna/neandertals-live-genome-sequencing-2010.html ]

      As you can see from Hawk’s article, this is (was) controversial, even if you try to separate between biological and fossil (morphological) species. And, mind, if it is not “species” it could be “races” with all the history, it could either help or hinder public discourse.

      Re sperm incompatibility as such, any specific numbers on the difficulty hasn’t been mentioned though, what I know of. Wouldn’t that be hard to model without knowing how often matings were attempted?

      IIRC there has now been 2 or 3 finds of successful interbreeding with Neandertahls. (One of which didn’t make it into the modern genome.) And we could count the same age Denisovan success as well. (And even the putative 4th crossing with a shadow species, which leading candidate could be a much older split of H. erectus.)

      Maybe hundreds of matings were attempted, but it sounds like a high number to me.

      • W.Benson
        Posted September 11, 2015 at 7:35 pm | Permalink

        I have no problem with being of hybrid origin. Do you?

        • Torbjörn Larsson
          Posted September 22, 2015 at 7:29 am | Permalink

          No. I just suppose I am a bastard either way. =D

          • Diane G.
            Posted September 22, 2015 at 4:31 pm | Permalink

            LOL!

      • Posted September 15, 2015 at 5:06 am | Permalink

        Very interesting Torbjörn! Thanks for the detailed answer

  41. Posted September 11, 2015 at 12:04 pm | Permalink

    Reblogged this on Monkey Dance and commented:
    I tweeted about this when I first saw the write up and will add comments later. Professor Ceiling Cat at Why Evolution is True has done a very nice write up and definitely worht the few minutes to read it.

  42. gravelinspector-Aidan
    Posted September 12, 2015 at 11:43 am | Permalink

    Exploration blogs.
    Following hints from my .ZA correspondent, here is the original blog post by the explorers about their discovery of an extension to “Rising Star”.
    It looks as if NatGeo are keeping the lid firmly on their investment, but the blog also re-posts a New Scientist article.
    Cartoon.
    More cool stuff.

    • Posted September 12, 2015 at 2:42 pm | Permalink

      Those are fantastic links! Especially that last one — it’s got a 3-D virtual tour of the cave system, complete with narration by two of the women who worked on the excavation.

      b&

      • gravelinspector-Aidan
        Posted September 12, 2015 at 4:26 pm | Permalink

        We did a point cloud on GG main chamber a few years ago – actually it was the week of the GPR. Then the machine was about a foot in each dimension (30 cm) ; they seem to have got smaller since, as one would expect. Smaller batteries too. And no laptop to pass the data to.

    • Posted September 12, 2015 at 2:58 pm | Permalink

      Also the FAQ:

      http://ewn.co.za/Features/Naledi/FAQ

      with lots of stuff directly addressing many of the questions here:

      Apart from the current complex route into the Dinaledi Chamber, has there ever been a more direct route into the cave? Our mapping indicates that the roof to the Dinaledi Chamber consists of a chert horizon which is unbroken. Likewise, on surface, above the cave there is no indication of a direct vertical entrance way into the chamber. In other words, we have found no evidence that there is, or ever was a more direct entrance into the Dinaledi Chamber.

      How do you know that there were no other entranceways into the Dinaledi Chamber? The sediments in the Dinaledi Chamber are different from the sediments in other chambers in the cave in a number of important ways: they are fine-grained and mud-rich, and contain no coarse-grained clastic components; they are relatively poor in quartz; and they are chemically distinct and derived almost completely from the cave itself. These sedimentary characteristics indicate that the Dinaledi Chamber was isolated from the earth surface and from other chambers in the Rising Star cave. The way the sediments are distributed in the Dinaledi Chamber, with fossil-bearing units accumulating below the current entry point indicate that this was always the entry point into the chamber, even at the time the fossils entered the chamber.

      …and an entire section on body disposal….

      b&

      • gravelinspector-Aidan
        Posted September 12, 2015 at 4:35 pm | Permalink

        I read that lot in the papers. I see where they’re coming from, being reduced to the present access route as the only one they can envisage. But having hauled 20 and 30 kilo bags of gear through tight cave, I really cannot envisage what mental process would lead to them doing that. Even if they actually lived in the “entrance series” (which from the video, doesn’t look exactly appealing) and wanted nearby disposal in a cave (understandable), it would still have been a LOT less work to lug the corpse out of the cave, across a kilometre or so of veldt, and deposit them in some other cave in the area.
        Which raises one intriguing possibility – if all the nearby caves were inhabited …
        Hmmm, I’m still unconvinced.

        • Posted September 12, 2015 at 5:38 pm | Permalink

          Another possibility…pretty much all extant human societies have, to some degree or another, various forms of initiation rituals that involve intentionally doing stupid shit. If they lived in the entrance cave (any signs of that?), some of their stupid shit could have included wandering through the inner cave; that, in turn could lead to familiarization with the passages.

          And it’s also not hard to see some sort of religious sentiment get attached…they’re showing extra respect to the dearly departed by burying them so far underground at such great personal risk to themselves.

          Wait — another key question!

          What would have been the physical characteristics of these hominins?

          …in relation to the petite young women who did all the heavy lifting in this dig?

          I’ll bet you a pint that the hominins were slightly smaller still, and I know the paper has described them as having physiology well suited to climbing.

          Almost seems like the trek, yes, would still have been a challenge for them…but nowhere near as challenging as it is for modern humans. The average amongst them may well have been better suited for caving than the champions amongst us.

          b&

          • gravelinspector-Aidan
            Posted September 12, 2015 at 6:12 pm | Permalink

            If they lived in the entrance cave (any signs of that?), some of their stupid shit could have included wandering through the inner cave; that, in turn could lead to familiarization with the passages.

            There’s no mention of them having searched the entrance passages for remains, but I’d be astonished if they hadn’t. Of course, the cave system has been known since some time in the 1950s, so even with the relatively small number of .ZA cavers there has likely been a lot of human (and other animal) footfall in the more accessible bits of the cave.
            I agree that “dare” or initiation could well lead to familiarisation with the deeper sectors of the home cave. But that still implies control of fire, to the extent that they can construct reasonably reliable light sources.
            Soot. If they had fire, then there should be soot.
            ‘Scuse me ; emails to write.

            • Posted September 12, 2015 at 6:22 pm | Permalink

              If those inquiries lead to somebody looking for (and especially finding!) traces of soot that haven’t yet been looked for, somebody owes me a pint….

              b&

              • gravelinspector-Aidan
                Posted September 12, 2015 at 6:51 pm | Permalink

                Hmmm, precisely no reference to presence of soot in either paper of the 4 supplementary info files.
                I should have looked for “ochre” too. And, for that matter, “pollen”. I don’t believe that they haven’t tried looking for pollen – though red sediment isn’t ever encouraging for palynology.

              • Posted September 12, 2015 at 7:06 pm | Permalink

                Interesting!

                I await reports on responses to your emails. I’m sure they must have thought of these sorts of things, and I have no doubt but that they would have been careful enough to preserve the possibility to perform such analyses in the future even if they haven’t.

                …would soot remain visible on the ceiling of (some parts of) a cave after millions of years? I’d think it’d fall off, but, if not…that would be humbling indeed…to see the soot from the smoke of some of the children of Prometheus himself….

                b&

              • gravelinspector-Aidan
                Posted September 12, 2015 at 7:11 pm | Permalink

                Soot deposits can certainly survive 50,000 years, and I see no reason to think it wouldn’t survive millions. Carbon isn’t good eats for anything.
                I certainly see carbonised fragments of organic material all through the fossil record.
                I recall (and mentioned in my email to Prof Berger) that there was recently dating work on a French cave (Cosquer, or Lascaux I forget which) which relied on flowstone which overlay soot used as a pigment.
                I suspect his mailbox is pretty full at the moment.

              • Posted September 12, 2015 at 7:15 pm | Permalink

                I trust you’ve had the foresight to jigger the ledger sufficiently that Prof. Berger owes you more pints than you owe him?

                b&

              • gravelinspector-Aidan
                Posted September 13, 2015 at 10:37 am | Permalink

                That sort of game has entertaining but less than productive escalatory spiral modes.
                Or are they descending spirals? Double helices.
                Oh yes, in deference to Crick and Watson at “The Eagle”, there must be a “double helix” drinking game somewhere. (There probably is ; probably many.)

              • Posted September 13, 2015 at 6:42 pm | Permalink

                I imagine therea be a single spiral drinking game upon which you know you’ve lost when you’re seeing a double helix instead.

              • gravelinspector-Aidan
                Posted September 14, 2015 at 8:15 pm | Permalink

                Try this for size. It needs a prop.
                Make a “double helix” of two bits of tubing (with confusing cardboard for phosphates, sugars and nucleotides). One end of the tubing goes into a bucket of beer, one into another bucket. First players don’t have to observe the helix too closely. but as you top up the beer bucket, and losers top up the other bucket with ex-beer (beer that has ceased to be? Beer that has dribbled out of the mortal coil? Beer that is on it’s way back to the brewery? Think of an euphemism.)

              • Posted September 14, 2015 at 9:34 pm | Permalink

                Sounds dangerous, but I think we can up the ante. In the beer bucket, we put Bud Light Lime, then as the game progresses we see who intentionally avoids the beer bucket for the beer that’s making its way through purgatory in hopes of purification.

          • gravelinspector-Aidan
            Posted September 12, 2015 at 6:24 pm | Permalink

            The H.naledi would have been considerably smaller than modern humans, which would make the access route less demanding. But such an arduous route to the cemetery implies a severe shortage of alternative cemeteries.
            This really is a complex find.

            • Posted September 12, 2015 at 6:45 pm | Permalink

              Again, I think we need to consider the possibility that the arduousness could have been a feature, not a bug. They weren’t disposing of stinky meat in the most convenient manner possible; they were conveying the dearly departed to their next destination.

              How many construction projects have been more arduous than the Egyptian Pyramids? The Egyptians had far easier ways of disposing of the bodies of their emperors….

              Obviously, I’m working under the hypothesis that they had at least a rudimentary form of language and culture, enough to support multi-generational traditions and maybe even some prototypically religious superstitions. More than is demonstrated by modern non-human apes, of course, but not necessarily an awful lot more. And if this really is a burial site, I don’t think those guesses are all that far out of line.

              b&

              • gravelinspector-Aidan
                Posted September 12, 2015 at 7:07 pm | Permalink

                That thing about

                an exposed, ∼15 m climb […] up the side of a sharp-edged dolomite block that has dislodged from the roof (the Dragon’s Back;

                does raise the possibility of a previous access route to the chamber under the “Dragon’s Back” …
                BUT, a route like that would probably pre-date the accumulation of the facies-1 material which forms part of the matrix to the bone deposit. Or would it? You know, I’m not sure. Mapping deposits in a cave is bloody difficult, and interpreting them is even harder.

  43. Dave R
    Posted September 12, 2015 at 1:06 pm | Permalink

    Creationist #1: Elizabeth Mitchell, Answers In Genesis-…”the preponderance of the evidence suggests they were animals, one of the variations that developed among apes.” https://answersingenesis.org/human-evolution/homo-naledi-new-species-human-ancestor/?utm_source=twitterfeed&utm_medium=twitter&utm_campaign=Feed%3A+AIGDaily+%28Answers+in+Genesis+Daily+Articles%29

    Creationist #2: Kurt Wise- “I think the case is very strong that these fossils are not just of the genus Homo, but are actually fully human (meaning they are descendants of Adam and Eve)”. https://www.worldmag.com/mobile/article.php?id=35172

  44. Diane G.
    Posted September 15, 2015 at 7:54 am | Permalink

    What an exhilarating, mind-stretching discussion! Thanks especially to Aidan, Torbjörn, sedgequeen, John Scanlon, nickswearsky, Ben, and everyone else for all the enlightening explanations and hypothesizing. What an amazing community we have here!

  45. Posted September 19, 2015 at 5:42 pm | Permalink

    The media coverage of this remarkable discovery has been very loose indeed. A pity. In terms of how all these discoveries fit together – well, I think a lot boils down to status among paleoanthropologists. Everybody wants to discover a new species. Were there that many? Maybe. But we don’t really know. There are still more gaps than otherwise, and the mechanisms by which the post-cranial form established with H. erectus (and shared by us) actually emerged seems something of a mystery. Doubtless more discoveries will uncover answers – or more arguments. But at least the science has got beyond the silly multi-regional theory which was in vogue when I was studying this field as an undergrad in the early 1980s.

  46. Torbjörn Larsson
    Posted September 22, 2015 at 7:33 am | Permalink

    Short update:

    Hawks has published two articles on the find.

    http://johnhawks.net/weblog/fossils/naledi/homo-naledi-homo-erectus-2015.html

    http://johnhawks.net/weblog/hawks/travel/rising-star-announcement-livestream-2015.html

    In the movie they say they have worked over a few dm, but the cave is 12 m deep. They estimate _several hundreds_ of individuals! Their burial hypothesis takes off from there (and the claim that these individuals didn’t all die at the same time, I guess from the differential movement of fossils).


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