A conundrum: What pollinates Venus fly traps?

The Venus flytrap (Dionaea muscipula) is a familiar carnivorous plant in the family Drososeraceae. But, unlike sundews or pitcher plants, it’s the world’s only animal-eating plant that actively snaps a trap to ensnare its prey. Here’s a video showing the traps, which are highly modified leaves:

(Small prey can escape the traps through the teeth, and some say that’s an adaptation in the plant to avoid wasting digestive energy on food of low nutritional value.)

The mechanism of trapping and digestion both involve counting by the plant (not conscious counting of course, it’s the summation of stimuli probably combined with some threshold). As Wikipedia notes:

The mechanism by which the trap snaps shut involves a complex interaction between elasticity, turgor and growth. The trap only shuts when there have been two stimulations of the trigger hairs; this is to avoid inadvertent triggering of the mechanism by dust and other wind-borne debris. In the open, untripped state, the lobes are convex (bent outwards), but in the closed state, the lobes are concave (forming a cavity). It is the rapid flipping of this bistable state that closes the trap, but the mechanism by which this occurs is still poorly understood. When the trigger hairs are stimulated, an action potential (mostly involving calcium ions—see calcium in biology) is generated, which propagates across the lobes and stimulates cells in the lobes and in the midrib between them. It is hypothesized that there is a threshold of ion buildup for the Venus flytrap to react to stimulation. After closing, the flytrap counts additional stimulations of the trigger hairs, to five total, to start the production of digesting enzymes. The acid growth theory states that individual cells in the outer layers of the lobes and midrib rapidly move 1H+ (hydrogen ions) into their cell walls, lowering the pH and loosening the extracellular components, which allows them to swell rapidly by osmosis, thus elongating and changing the shape of the trap lobe. Alternatively, cells in the inner layers of the lobes and midrib may rapidly secrete other ions, allowing water to follow by osmosis, and the cells to collapse. Both of these mechanisms may play a role and have some experimental evidence to support them.

You can look up various evolutionary scenarios for the evolution of this complex adaptation, but we’re pretty clear on the selection pressure: like other carnivorous plants, the Venus fly trap grows in nutrient-poor soils like bogs, and trapping insects is a way to get the essential nutrient nitrogen lacking in those places. At present the species range is limited to small areas of North and South Carolina, as this interactive range map shows (extinct populations are dark). If you go to the map, you can see where other populations have been introduced.

 

The species is threatened by habitat loss and collectors, is listed as “vulnerable” and there’s a petition for its listing as “endangered.” I had one that I bought as a kid, but I think I killed it (as kids do) by overfeeding it.

Now the species, like all carnivorous plants, is an angiosperm—that is, it has flowers, and must be pollinated (in this case, cross-pollinated). And that raises a problem: How can you get pollinated if you trap most insects that land on your pads? If a pollinator stands a chance of being eaten when it’s attracted to your flowers, then that’s powerful selection against pollination!

Now pollination does have an upside: the flowers have nectar and so the pollinator gets some nutrition. But the traps secrete nectar, too: that (and perhaps the color) is why they lure insects.

But one would think that the chance of being killed by investigating the attractive pads exceeds the marginal benefit of getting nectar from the flower, and so one wonders how this plant gets by. Any insect that was attracted to the flower for pollinating stands a good chance of being killed, and this would select against the evolution of traps as well as against insects’ attraction to traps attraction. There are thus two conflicts:

Insects: pollinating and getting nectar versus being trapped
Plants: getting pollinated versus getting trapped food

Yet traps and pollinators evolved. How?

Well, two solutions immediately came to mind. One is that the flower grows far away from the traps, so insects attracted to the flower might avoid the traps (or those individuals attracted to both flower and trap would have their genes removed by selection from the population). And, sure enough, the Venus fly trap flower is physically far removed from the traps.

Another possibility, which turns out not to be the case, is that the the leaf-traps might not be active at the same time as flowering, so that although selection might operate during “trap season” against insects attracted to the traps, it would be mitigated or reversed by selection to be attracted to the flower in “non-trap” season. But, as a new paper by Elsa Youngsteadt et al. in the American Naturalist reports (free access to the pdf; reference below), there’s substantial overlap in the period when both flowers and traps exist.

There are other explanations.  It’s likely the flowers evolved first, and possible that a guild of pollinators evolved an attraction to them. If the traps then evolved later, a different group of insects might have been attracted to those, so the trap/pollination conflict wouldn’t exist for any species. (There would still be the problem of selection against those individuals who were attracted to traps, though.)

At any rate, to see if there is a conflict between pollination and trap-visiting for the insects, and between food and pollination for the plants, you have to find out who pollinates Venus fly traps, and who gets caught in the traps. Surprisingly, until this paper was published, nobody knew squat about that.

Youngsteadt and her collaborators spent 29.5 hours sampling many insects that pollinated or visited D. muscipula at four sites on four days over the blooming period. They identified both insects that got caught and insects pollinating the flowers, dividing them into higher taxa if they couldn’t identify them as to species.  They also washed the pollen off of each flower visitor, estimated how much of the pollen came from the Venus fly trap, and calculated an index of “pollinator importance,” which is the relative abundance of a given pollinator group among all pollinators multiplied by the fidelity of the insect to the plant (or rather, arthropods, as there were some spiders, too) multiplied by how much D. muscipula pollen the arthropod carried.

Results: There wasn’t much overlap between the species that got caught in the traps and the species pollinating the flowers. The most important pollinator by far was the sweat bee Augochlorella gratiosa, followed distantly by the longhorned beetle Typocerus sinuatus and the checkered beetle Trichodes apivorus.

40% of the trapped individuals were spiders, and among the 58% that were insects, most were ants and beetles not represented by the two important beetle pollinators. Here’s a diagram from the paper of the overlap between pollinators and prey showing the small overlap between species:

(From the paper): Figure 2: Quantitative network illustrating the extent of overlap between Dionaea muscipula prey and flower visitors. Only flower visitors that carried pollen are shown. In each network, block heights in the left bar represent the relative sample sizes of arthropods from flowers and traps; block heights in the right bar represent relative abundance of each taxon in the combined sample from traps and flowers. Taxa shared between traps and flowers are connected both to traps (light gray connections) and to flowers (dark gray connections); shared taxa are expanded in the inset. Data underlying the figure are deposited in the Dryad Digital Repository: http://dx.doi.org/10.5061/dryad.p8s64 (Youngsteadt et al. 2017).

The upshot: Now this shows that the pollinators don’t face the problem of getting caught in the traps, as they don’t seem to visit the traps. But what this means is unclear. There are still several alternatives: the pollinators were selected to avoid visiting traps, or the leaves and flowers evolved at different times, with flowers attracting species that weren’t attracted to the later-evolving traps. The authors add “selection for divergence in the niches occupied by flowers and traps”, which is selection to avoid competition with other species, but I don’t see the traps as “niches”, any more than the mouth of a polar bear is a “niche” for a seal.

What the paper shows overall, it seems to me, is simply that the conflict between pollination and being eaten doesn’t exist for most insects. But it doesn’t explain whether that conflict existed at one time, nor why insects and other species haven’t been selected to avoid the traps. But of course adaptation in prey isn’t perfect: if it were, there would be no predators.

h/t: Matthew Cobb

_________

Elsa Youngsteadt, E. R. E. IrwinA. FowlerM. A. BertoneS. J. GiacominiM. KunzD. Suiter, and C. E. Sorenson. 2018. Venus flytrap rarely traps its pollinators. The American Naturalist, published online

72 Comments

  1. Vaal
    Posted February 7, 2018 at 10:52 am | Permalink

    Very fascinating!

    I had Venus fly traps when I was young. It was a fun “monster plant” for a kid to care for.

    • bundorgarden
      Posted February 7, 2018 at 5:08 pm | Permalink

      I still have them, and I am old. They are easy to keep, but I reckon 99.9% of those sold would die an early death.

      • Brian salkas
        Posted February 7, 2018 at 8:32 pm | Permalink

        I haven’t read the paper yet, I also am far from knowledgeable on this topic, but I do know that the traps can only catch one meal per week or so (please fact check me on that) and grow around six traps per plant. If that is the case, then that might mean there is not much conflict between eating and reproducing. If 20 insects visit the plant in a week – which is a very conservative estimate – then there would still be 14 insects left to potentially pollinate the flowers.
        Although, as pointed out by Jerry, the flowers are very far away from the traps and the traps attract mostly different insects than the flowers. It would be odd if those were not adaptions to improve reproductive success.

  2. glen1davidson
    Posted February 7, 2018 at 10:55 am | Permalink

    The traps and the flowers are certainly different colors, so I wonder if that’s important in attracting pollinators to flowers and prey to the traps. Meat eaters, whether the meat is dead or live, such as the ants and spiders (and beetles, depending on species) are probably attracted to the red of the traps, even if the “reward” is sweet nectar.

    Glen Davidson

    • glen1davidson
      Posted February 7, 2018 at 11:22 am | Permalink

      I don’t know if spiders are attracted to red and/or meat, and if they are it’s almost certainly not to eat it. But some spiders could be attracted to meat in order to eat insects that it attracts.

    • W.Benson
      Posted February 7, 2018 at 1:14 pm | Permalink

      Hymenoptera, such as wasps and bees (the principle pollinator), are notorious for not being able to see the color red. The flowers seem to be blue-white, perfect for a “bee-flower”. The trap leaves are red and would “appear” gray or black to a bee. After finding a good food source, bees tend to learn to identify it and become temporary specialists until it runs out or something better comes along.

    • loren russell
      Posted February 7, 2018 at 1:54 pm | Permalink

      This paper [R.Zamora, 1999 Ecology 80:786-795] confirms the difference in leaf and flower color in ensuring effective pollination for a butterwort. Butterworts [Pinguicula], like the unrelated sundews use a sticky-trap approach, and the distinctly yellowish leaves pre-invented the yellow-card traps we see in greenhouses. Butterwort flowers are usually contrasting in color to the foliage [common species in temperate N.Am and Europe are violet or white, but just about any color in warmer parts of the world], and have a nectar spur that selects for long-tongued pollinators. The Zamora article shows that a wide range of bees, flies, and lepidoptera pollinate the flowers. The more agile bees and hoverflies pollinate without getting caught. Butterflies can pollinate but often end up as lunch…

  3. BobTerrace
    Posted February 7, 2018 at 10:56 am | Permalink

    Another “which came first…” problem solved. 👍

  4. Posted February 7, 2018 at 11:09 am | Permalink

    Sounds like fly trap is a misnomer since most of the trapped are spiders, beetles and ants.

    • loren russell
      Posted February 7, 2018 at 1:44 pm | Permalink

      I grew Dionaea for several years in an artificial bog [in western Oregon], along with pinguiculas [butterworts], pitcher plants [Sarracenia, Darlingtonia], and a variety of non-insectivorous plants. My flytraps seemed to catch opilionids [daddy-longlegs] more than any insect. Touching to see the last twitches of the longlegs poking out of the trap.

      • Brian salkas
        Posted February 7, 2018 at 8:34 pm | Permalink

        well venus-opilionid-trap doesn’t quite have the same ring to it…

  5. Darrin Carter
    Posted February 7, 2018 at 11:16 am | Permalink

    Post to support science articles.

    • davidintoronto
      Posted February 7, 2018 at 12:33 pm | Permalink

      Yes; me as well also.

      • Jeff Chamberlain
        Posted February 7, 2018 at 8:57 pm | Permalink

        Likewise.

  6. Christopher
    Posted February 7, 2018 at 11:28 am | Permalink

    Excellent! I had a flytrap which I kept going for a good several months last year, from balky finding the sun/moisture/ food balance, unfortunately it got blown over from a wind gust through an open window and sat upside down for 24 or more hours. They don’t survive well after being flattened. 😵

  7. Ken Pidcock
    Posted February 7, 2018 at 11:35 am | Permalink

    40% of the trapped individuals were spiders

    Well, that’s disappointing. 🙂 I’ve always thought of spiders as more clever than that.

    • loren russell
      Posted February 7, 2018 at 3:49 pm | Permalink

      Two more legs, equals more taps crossing the trap equals more summing across the nom-inator..

  8. Jacques Hausser
    Posted February 7, 2018 at 11:37 am | Permalink

    Did the authors test if the attractant (nectar) is different in traps and flowers ?
    As for the niche question: from the point of view of the flowers, the traps are an unavoidable part of the environment which can deprive them (the flowers) of polinisators. Thus, if the traps have to be maintained for the survival of the plant, any characteristic of the flower attracting insects uninterested in the traps would be selected. And reciprocally.

  9. Mark Shields
    Posted February 7, 2018 at 11:38 am | Permalink

    One correction and one comment. D. muscipula is not the only plant species that actively traps animals in a snap trap. Its close relative, the waterwheel plant (Aldrovanda vesiculosa) of the Old World, also uses a snap trap, but it is submerged under water.

    The reason flytraps capture so many spiders and ants is because those are ground-dwelling, crawling arthropods and the traps of Dionaea are in a basal rosette at or near ground level. Spiders and ants simply stumble into the traps (although ants also may be attracted to trap secretions). A flying insect, such as a sweat bee, spends very little time walking around on the ground so is unlikely to get trapped.

    • Posted February 7, 2018 at 12:04 pm | Permalink

      I hadn’t heard of the Waterwheel. I Googleated that and those plants are really cool. Here’s a video of them closing. Very fast, especially for something moving underwater.

    • Posted February 7, 2018 at 12:23 pm | Permalink

      So the waterwheel likely traps aquatic arthropods, and I read that its flower is above water. So there is not much conflict of interest here.

      • glen1davidson
        Posted February 7, 2018 at 1:00 pm | Permalink

        I was thinking that if the Venus Fly-Trap evolved from an aquatic species, the flower would already be growing well away from the rest of the plant.

        Vice versa too, of course, but most water plants do have extended flower stems anyhow, so I like the idea of the flytrap evolving from an aquatic ancestor better than the other way around.

        Glen Davidson

    • garman
      Posted February 7, 2018 at 12:35 pm | Permalink

      I wonder do most trapped arthropods “stumble in” or are they attracted?

      • glen1davidson
        Posted February 7, 2018 at 12:40 pm | Permalink

        Good question. My sense is that ants, anyhow, aren’t likely to walk over a plant unless there’s some indication of food on or in it, like a scent.

        Otherwise, they’re mostly walking on the ground, leaf litter, whatever.

        Glen Davidson

    • glen1davidson
      Posted February 7, 2018 at 8:56 pm | Permalink

      The snap trap only evolved once, according to research cited by Wikipedia, so apparently before Venus flytraps and waterwheels diverged. Not surprising, but it wasn’t certain just from the fairly close relationship.

      But it isn’t just found in the Old World any more. It’s been introduced into the US, and some have been found in New York, Virginia, and New Jersey. I just thought I’d mention it in case Americans would like to look for them.

      Glen Davidson

  10. Barry Lyons
    Posted February 7, 2018 at 11:41 am | Permalink

    Fascinating! I hadn’t thought about the pollinating conundrum until I read this piece. Good post!

  11. Howard Neufeld
    Posted February 7, 2018 at 11:54 am | Permalink

    An excellent discussion. We are currently growing a number of these (and sundews too) in plant physiology class for students to observe. Some may do projects on the plants eventually. We may measure photosynthesis on the blade and trap and compare.

    The subject of pollinators vs trap prey had never occurred to me, so thanks for bringing this to my attention.

    Darwin thought this a most amazing plant. And it is.

    • Posted February 7, 2018 at 12:24 pm | Permalink

      I remember reading how he was very puzzled, wondering if they somehow had muscles. Not sure if he figured out the mechanism.

  12. Posted February 7, 2018 at 11:58 am | Permalink

    Could it be that the pollinators (mostly) fly while those trapped (mostly) don’t?

    Here’s what I’m thinking. The spiders, ants and some beetles stumble into the trap as they are crawling over the plant – perhaps even lured by the trap(?). The pollinators, on the other hand, rarely alight on the trap (thereby getting caught) as the flowers, which is what they are after, are at some distance away. Maybe the difference in trap rate is a reflection of the difference in the way the two groups interact with the plant?

    Just one of my guesses.

  13. Posted February 7, 2018 at 11:59 am | Permalink

    Fascinating – I am not sure I have ever seen a VFT flower – until now. I certainly have no memory of them in the live plants I saw in the Montreal botanical gardens years ago. (I *think* that’s where I saw one!)

  14. busterggi
    Posted February 7, 2018 at 11:59 am | Permalink

    Curse the arthropods for not having invented writing so they could leave us a history of how this happened. Then again, the font would be awfully tiny.

  15. Janet
    Posted February 7, 2018 at 11:59 am | Permalink

    Is it possible fly traps are evolutionary dead ends in that they do not reproduce successfully sexually? That their spread is primarily via asexual reproduction? Said another way, perhaps those members of a population who are good at sexual reproduction via flower fertilization are also poor at obtaining nutrition and die out.

    • Posted February 7, 2018 at 12:21 pm | Permalink

      I don’t know if fly traps produce viable seed but I think they do (why else study their pollinators). Some plants, like dandelions make flowers and even attract pollinators, but their embryos are not produced by meiosis – IOW, the flowers are reproductively fake; despite producing flowers, they reproduce asexually. So maybe that’s true of the fly traps. I dunno.

      But that doesn’t make them “evolutionary dead ends”. In fact, I’d venture to say most life on earth -if you enumerate them- reproduces asexually.

    • glen1davidson
      Posted February 7, 2018 at 12:26 pm | Permalink

      Here, if you’d like to buy Venus Fly-Trap seeds

      I assume that they can sprout and grow.

      Glen Davidson

      • glen1davidson
        Posted February 7, 2018 at 12:28 pm | Permalink

        I don’t know why the link doesn’t work.

        Retry:

        https://tinyurl.com/ycd6q5z7

      • gravelinspector-Aidan
        Posted February 7, 2018 at 1:09 pm | Permalink

        When we had a couple of VFTs on the windowsill, we tried collecting the seed – tiny black ones, as I recall – but never got any of it to germinate. With a significant under-representation of verdant thumbs in the house though, that signifies little.

        • een
          Posted February 7, 2018 at 5:29 pm | Permalink

          I’ve got a modest range of carnivorous plants, but the VFT’s never did well in my temperate climate until I got a glasshouse. Most cultivation advice on VFT’s is to nip off the flower stalks when they’re emerging, as they take a fair bit of energy for the plant to produce, and the seeds don’t germinate well. The plants also reproduce vegetatively, forming a couple of offshoots each year which can be potted out separately. That seems to be quicker and produces stronger young ‘uns.

    • Mark Shields
      Posted February 7, 2018 at 12:44 pm | Permalink

      Flytraps are prolific seed producers and in the wild reproduce sexually almost exclusively. The fossil record, albeit sparse, indicates that they have been around a very long time.

      • Janet
        Posted February 7, 2018 at 1:16 pm | Permalink

        Thank you for this info, Mark. That does fit the data presented above better.

        • Mark Shields
          Posted February 7, 2018 at 5:05 pm | Permalink

          You’re welcome, Janet! I live in se NC and have hundreds of flytraps growing on my property. I propagate them from seed to expand my population. Seeds remain viable for only a few months at ambient temperatures, but can be kept refrigerated for years with little decline in germination rates. Interestingly, in the wild the seeds are dispersed from the dried capsules mainly by the impact of raindrops.

  16. David Fuqua
    Posted February 7, 2018 at 12:23 pm | Permalink

    Very interesting. I have read other articles about the flytrap but they never mentioned the problem of pollination.

    Hurrah for Evolution!

  17. Posted February 7, 2018 at 12:28 pm | Permalink

    Good story.

  18. rickflick
    Posted February 7, 2018 at 12:32 pm | Permalink

    My first thought was that the flowers and traps have distinct chemical odors. Some insects are attracted to one and some are attracted to the other scent. This could occur without any adaptation on the part of the insects. It has the advantage for the plant of dividing the insects into convenient groups.

    • Posted February 7, 2018 at 1:46 pm | Permalink

      A logical hypotheses. And testable.

  19. Darren Garrison
    Posted February 7, 2018 at 12:45 pm | Permalink

    The “flowers and traps evolving separately” idea doesn’t seem to hold water the clade containing Venus Flytraps and Waterwheels is a sister clade to the Sundews–the common ancestor of them all was probably sundewish. So the real question is about the evolution of flowers vs. sticky traps, not flowers vs. snap traps. And if you google for images of Sundew flowers, you’ll see that they often have much shorter stems than VFT flowers.

    https://www.quora.com/What-is-the-evolutionary-history-of-the-Venus-flytrap

    You might also be interested to see flowers of the Sarracenia pitcher plants:

    http://s313.photobucket.com/user/darrengarrison/library/carnivorous%20plants?sort=3&start=all&page=1

  20. Mark R.
    Posted February 7, 2018 at 12:50 pm | Permalink

    Thanks, I really appreciated this paper. I enjoy collecting and growing carnivorous plants in my greenhouse. They grow well in a greenhouse year-around here in Washington. I have 2 Venus fly traps, and now I’ll enjoy them even more. Like Venus fly traps, all the varieties of sundews I have also grow long flower stalks, I imagine for the same reason that Venus fly traps do.

    • Mark R.
      Posted February 7, 2018 at 12:51 pm | Permalink

      “paper”? Post. 🙂

    • Posted February 7, 2018 at 1:03 pm | Permalink

      Do you have to feed them? Or are there enough captures in your green house?

      • Mark R.
        Posted February 7, 2018 at 2:00 pm | Permalink

        There are enough insects (mostly midges from a turtle pond) and spiders that I don’t have to feed them. There isn’t any ‘food’ during the winter months though, but that doesn’t seem to be detrimental.

      • glen1davidson
        Posted February 7, 2018 at 2:00 pm | Permalink

        They don’t have to be fed, so long as they’re getting enough nutrients otherwise.

        But why would you have any of them if you weren’t feeding them, or at least watching to see what they catch?

        Glen Davidson

  21. Posted February 7, 2018 at 1:47 pm | Permalink

    Until now, I had no idea that Venus traps can die of overeating! (I have never owned one.)

  22. Posted February 7, 2018 at 2:51 pm | Permalink

    Reblogged this on The Logical Place.

  23. Diki
    Posted February 7, 2018 at 3:50 pm | Permalink

    As my old mother used to say to me as a teenager when warning me of the perils of unprotected sex, “it only takes one stray sperm”. How much pollen is needed and how often? Perhaps there is such an abundance of insect visitors the plants can get quite enough food and sex.

  24. nicky
    Posted February 7, 2018 at 3:55 pm | Permalink

    Fascinating and highly interesting.
    There is another detail, I never knew that the ‘fly traps’ had such a very limited spread in the Carolinas. I somehow thought that they would have a wide spread such as drosera, basically found on all continents (except Antarctica). I’m stunned.
    Is the drosera technique more efficient? Or is it just an ‘evolutionary happenstance’?

    • Mark Shields
      Posted February 7, 2018 at 4:58 pm | Permalink

      Fossilized pollen of Dionaea from the mid-Miocene and Pliocene (roughly 15-2.5 million years ago) has been found in Europe, indicating that flytraps were once much more widespread than today. Why the current range is restricted to se NC (where I live) and ne SC could be just chance. They grow well in other states where they have been transplanted (eg. New Jersey and Florida).

      • glen1davidson
        Posted February 7, 2018 at 5:09 pm | Permalink

        Glacial periods could have plenty to do with it.

        They’re not great at taking the cold, yet they seem to need mild winters. So with ocean levels going up and down, the cold likely killing them off in the interior, and unable presently to spread to the tropics, flytraps may have been close to extinction. They survived near the coast it looks like.

        Are they good at dispersing their seeds? If not, they wouldn’t spread too well after the last glacial period.

        • Mark Shields
          Posted February 7, 2018 at 8:53 pm | Permalink

          I agree that glaciation certainly could have limited them from extending their range farther north, but why would they not occur farther south than the Carolinas? Flytraps are quite fire-dependent and are quickly shaded out by taller species when fire is suppressed. They also are well-adapted to sandy, moist, nutrient-poor soils. Such habitats, mainly associated with Longleaf Pine ecosystems, occurred historically throughout much of the coastal plain of the se US.

          My experiments on seed dispersal indicate that seeds do not travel very far from the parent plant. Initial dispersal occurs mainly by seeds being dislodged from capsules by raindrops, rarely moving more than 1 m from the parent. The seeds are highly hydrophobic and can float for months, which would allow them to secondarily disperse in surface runoff after a thunderstorm. However, elevation gradients are very low in the coastal plain and seed viability declines dramatically after a few months. This would limit dispersal and could easily result in populations becoming isolated. Such populations would be more vulnerable to extinction. Perhaps those in the Carolinas were just lucky.

          • glen1davidson
            Posted February 7, 2018 at 11:11 pm | Permalink

            I guess I was thinking that if glacial periods tended to reduce the range to near the coasts, then you have “sea rise” and fall (sometimes fairly quickly), Venus flytraps might have a hard time adapting. So maybe they hang on in a place or two in the Carolinas, at least in part by chance, and not in other places, again at least partly by chance. It’s not obvious that there was anything really special about the Carolinas, I just think it was probably tough for flytraps to hang on at all, but fortunately a few did.

            Take it for what it’s worth, I’m mostly guessing.

            Thanks for the information on the seed dispersal, it’s quite interesting since I was curious and hadn’t found any good answers.

            Glen Davidson

  25. ThyroidPlanet
    Posted February 7, 2018 at 4:42 pm | Permalink

    Hey

    Am I the only one who missed this in email?

    Or maybe I too aggressive with the trash can icon

    • ThyroidPlanet
      Posted February 7, 2018 at 4:49 pm | Permalink

      Sorry – found it.

  26. S.K.Graham
    Posted February 7, 2018 at 4:47 pm | Permalink

    Turn your thinking around: the traps had to be selected to be attractive to the prey species. Or at the very least non-threatening.

    It stands to reason that something about the traps mimics scents and color patterns of sources of food, safety, or other needs of the prey.

    There would, of course, be an arms race here. Prey would be selected to distinguish traps from safe places, and traps would be selected to minimize such detectable differences.

  27. Posted February 7, 2018 at 7:11 pm | Permalink

    Love the science posts. Especially carnivorous plants!

  28. Posted February 7, 2018 at 8:17 pm | Permalink

    This stuff is so much fun!

  29. Brian salkas
    Posted February 7, 2018 at 8:45 pm | Permalink

    “There are still several alternatives: the pollinators were selected to avoid visiting traps, or the leaves and flowers evolved at different times, with flowers attracting species that weren’t attracted to the later-evolving traps.”
    I wonder, given that the flowers branch out away from the rest of the plant so far, if the mutations for different coloration for flowers (white) and traps (red) did not happen until after the flowers evolved to be further away from the plant. My hypothesis: The flowers grew away from the rest of the plant before they evolved to attract different insects. If they always attracted different insects to begin with, then they never would have had to be so far away from the traps in the first place.

  30. Dale Franzwa
    Posted February 8, 2018 at 12:05 am | Permalink

    Excellent.

  31. Posted February 8, 2018 at 5:21 am | Permalink

    Wow! utterly fascinating! I hope more is done on this! Can’t wait!

  32. Paul Dymnicki
    Posted February 11, 2018 at 8:54 am | Permalink

    This is why I love science.


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