The Big Kerfuffle about Kin Selection (i.e., Nowak et al. versus The World) has finally made the papers: today’s Boston Globe has a piece about it called “Where does good come from?: Harvard’s Edward O. Wilson tries to upend biology again.” I’m not going to reiterate the whole debate, but simply want to give and comment on a few quotes from the paper. I thought the piece was pretty fair; when I talked to the writer, Leon Neyfakh, he seemed pretty much at sea about what kin selection and group selection really were, but he’s done a creditable job on the article.
But of course the whole controversy isn’t really a fit subject for a newspaper article, for it’s not a controversy at all: it’s simply two guys and a woman deeply misunderstanding evolution and trying to parlay this misunderstanding into fame. Had an identical paper not borne the names of Martin Nowak and E. O. Wilson, Neyfakh wouldn’t have written this piece.
Some quotes:
On a recent Monday afternoon, the distinguished Harvard biologist Edward O. Wilson was at his home in Lexington, talking on the phone about the knocks he’s been taking lately from the scientific community, and paraphrasing Arthur Schopenhauer to explain his current standing in his field. “All new ideas go through three phases,” Wilson said, with some happy mischief in his voice. “They’re first ridiculed or ignored. Then they meet outrage. Then they are said to have been obvious all along.”
As one of my colleagues said dryly when he read that, “Wilson seems to have missed the point that you need a new idea before you can get to go through those phases!”
“Kin selection is wrong,” Wilson said. “That’s it. It’s wrong.”. .
Over the course of subsequent decades, Wilson came across evidence that made him doubt the connection between genetic relatedness and altruism. Researchers were finding species of insects that shared a lot of genetic material with each other but didn’t behave altruistically, and other species that shared little and did. “Nothing we were finding connected with kin selection,” Wilson said. “I knew that something was going wrong — there was a smell to it.”. . .
Saying that kin selection doesn’t feed into eusociality (societies in which a sterile worker caste tends one or a few reproductive individuals) because some haplodiploids aren’t eusocial and not all eusocials are haplodiploid is like saying that smoking isn’t associated with lung cancer because some smokers don’t get lung cancer and some people who get lung cancer didn’t ever smoke. The question is whether there is an apparently causal association between relatedness (i.e., via inclusive fitness) and altruism. And there is. We’ve long ago realized that haplodiploidy may not be the key factor in the evolution of eusocial insects, but relatedness certainly is. The ancestors of all eusocial insects, including non-haplodiploids like termites, mated only once rather than multiple times, which increases relatedness among their brood; this is exactly what you’d predict if relatedness were important here. Further, “cooperative breeding” in birds, in which the young stay at home and help mom and dad rear the next batch of their brothers and sisters, is correlated with lower promiscuity of the parents. That’s again explained by inclusive fitness, for you’d have less “genetic interest” in rearing future siblings if they had a different father from you (that would reduce your relatedness to future siblings by half).
Anyone who says that “kin selection is dead” is deeply muddled. What is parental care, after all, but a special case of kin selection? Why do Ma and Pa Eagle stay at home and tend the eaglets until they fledge? Why don’t they just go off and build another nest? The reason, of course, is because each parent is related by half (50% sharing of genes) with each chick, so their genes for parental care will be carried in those chicks. This is simply the most obvious case of kin selection, but the principle surely applies to lesser degrees of relatedness.
Dawkins makes strong judgment on the paper:
Richard Dawkins, who played a crucial role in popularizing kin selection with his 1976 book, “The Selfish Gene,” said last week that he has “never met anybody apart from Wilson and Nowak who takes it seriously.” . .
I think the other Wilson—David Sloan Wilson—takes it seriously.
Wilson is not arguing that members of certain species don’t sacrifice themselves for the benefit of their relatives. They do. But it’s his position that kinship and relatedness aren’t essential in causing the development of advanced social behaviors like altruism — that the reason such behaviors catch on is that they’re evolutionarily advantageous on a group level. That socially advanced organisms end up favoring their kin, Wilson argues, is a byproduct of their group membership, not the cause.
“It’s almost universally regarded as a disgrace that Nature published it,” Dawkins said. “Most people feel the reason they published it was the eminence of Wilson and Nowak, not the quality of the paper.” . .
Dawkins is right, of course. As I’ve said before, if the paper were published by three schmoes from Unknown University, it would have been rejected out of hand. Nature screwed up badly on this one, but of course the editors are rubbing their hands and chuckling over all the publicity they’ve gotten—at the expense of good science.
And yay for me and Dave Queller:
For Wilson to reject kin selection this late in his career has bewildered his many admirers. “It’s sad — he’s already an enormously famous and respected scientist, and it just sort of tarnishes him in people’s eyes,” said Jerry Coyne, the University of Chicago biologist who has written disapprovingly of Wilson’s latest work on his blog. Yet Wilson said he doesn’t have a choice in the matter. “I think that’d be a pretty poor scientist, who couldn’t reverse his view from new evidence,” he said. . . .
Many biologists find these assertions baffling. Said David Queller, a biologist at Rice University who spearheaded the letter to Nature that was signed by 136 other scientists: “At some really fundamental level I don’t understand what Ed Wilson is trying to get across, and I think that’s the response of most of the community.”
Nowak arrogantly responds:
That’s exactly the problem, according to Nowak, whose new book, “SuperCooperators,” co-written with Roger Highfield, summarizes his work as a mathematician on the origins of advanced social behavior. “They don’t know what they’re arguing against,” Nowak said recently at his office, where an oversize print of the Nature cover hangs on the wall. Specifically, Nowak explained, the critics don’t understand the math, and moreover, they don’t realize that the math is the most important part. . .
Yeah, right: 140 biologists, many of whom are mathematical biologists or deeply involved in theory (Dave Queller and Stuart West are just two among many), all fail to grasp what they’re arguing against! Well, those who have vetted the math realize that Nowak et al.’s model says absolutely nothing about a possible connection between relatedness and the origin of eusociality. That’s because their own model does not explore what happens when one varies the degree of relatedness! It therefore can’t say anything about whether relatedness is important in the evolution of eusociality. Responding to this, my colleague remarked, “This is like making three types of jam, where two are nice and one is gross (strawberry, gooseberry and oak leaf), and then saying that because the amount of sugar used wasn’t varied in these three jams (all were about 50% sugar) that sugar doesn’t matter to whether the jam tastes nice.”
Re whether kin selection is, as Nowak et al. assert strongly, something completely different from natural selection, Richard and I had something to say. I’m particularly proud of my analogy:
At a very basic level, critics feel Wilson and his coauthors are wrong to treat kin selection as something separate from natural selection. As Dawkins explains it, kin selection is not a distinct process but a necessary consequence: a subset, rather than an add-on. “What they’re missing is the logical point that kin selection is not separable from neo-Darwinian natural selection,” Dawkins said. “To separate them off would be like talking about Euclidean geometry without talking about the Pythagorean theorem.”
Coyne put it even more simply: “It’s like saying that Chardonnay is not wine.” . . .
Wilson again argues for the non-importance of relatedness:
Wilson is not arguing that members of certain species don’t sacrifice themselves for the benefit of their relatives. They do. But it’s his position that kinship and relatedness aren’t essential in causing the development of advanced social behaviors like altruism — that the reason such behaviors catch on is that they’re evolutionarily advantageous on a group level. That socially advanced organisms end up favoring their kin, Wilson argues, is a byproduct of their group membership, not the cause. . .
Well, if you want to see if kinship is a causal factor in the evolution of any trait, you must make a model in which group sizes and dynamics are the same but the degree of kinship varies. That is exactly what Nowak et al. did not do. Wilson has no idea what he’s talking about here.
And watch out for more evolutionary psychology to come!
So far, Wilson has stopped short of extending his new ideas about the evolution of social behavior to the human race. But that’s not going to last. Asked last week whether group selection happens in humans, Wilson said, “Yes, emphatically.”
“Human beings have an intense desire to form groups, and they always have,” Wilson said. “This powerful tendency we have to form groups and then have the groups compete, which is in every aspect of our social behavior…is basically the driving force that caused the origin of human behavior.”
Wilson will elaborate on this view in his next project, a book he’s tentatively calling “The Social Conquest of Earth,” which he said will be published by W. W. Norton next year. In it, he said, he will explain how socially advanced species have come to dominate the earth, and will lay out a “reexamination of human evolution” informed by his recent turn towards group selection.
It is possible that some kind of group selection for altruism occurred in early human lineages, based on differential reproduction of groups with different degrees of “morality.” But it could also have involved kin selection if, as is likely, members in early human social groups were related. And the evolution of moral codes and behaviors could also have involved individual selection: individuals who behaved nicely could have reaped reproductive benefits since groups were small and individuals intimately acquainted with each other, so they could remember and reward those who were nice, with the expectation of getting the same by behaving the same. Regardless, most animals don’t live in such small groups nor have a memory for interpersonal dynamics. And of course we know, from other observations (evolution of sex ratio, preferential care for relatives, cooperative breeding, etc.) that kin selection certainly does operate in nature.
I’ve tended to see group selection as a kind of out-growth of kin selection. Seeing the group as an extended kin of varying relatedness. I have a hard time conceiving of a mechanism for the reverse, like Wilson et al. are arguing.
I work with bacteria, so this is a bit out of my realm of expertise, but from a semi-lay interpretation, it seems like Wilson et al. may have this exactly backwards.
Naturally, it’s a bit more complicated than that, but do I have the gist of it?
That’s my take on it, too.
Unless Nowak et al. are arguing against common descent, every living organism on this planet (outside of Craig Venter’s labs, of course) is a cousin of some sort or other. They seem to be arguing that kin selection applies to organisms closely related enough to breed successfully, but not to organisms that are only a generation or so distantly related.
Is that a fair characterization? If so, can anybody help me understand why they think the distinction is necessary?
Cheers,
b&
I only have a slightly amusing anecdote to contribute to this, being a non-biologist who can only admire articles like this from afar.
I became aware of this debacle only when a friend of mine drew my attention to an article on the publication of “SuperCooperators”. Because I hang out on the websites of certain professors who seem to know a thing or two about evolution and biology I had a quick search and noticed Richard Dawkins’ comment about the book, and then the subsequent analysis of the kin selection kerfuffle. I sent my friend links to the comment and the related posts on the response to Nowak’s 2010 paper.
My offerings were received with something akin to cold fury, and a disgruntled utterance that Dawkins “did not understand evolution very well”. My friend does not appear to be talking to me anymore.
Nice article, like usual, but there is some serious confusion about the use and interpretation of mathematical models. Here’s an example.
“Well, those who have vetted the math realize that Nowak et al.’s model says absolutely nothing about a possible connection between relatedness and the origin of eusociality. That’s because their own model does not explore what happens when one varies the degree of relatedness!”
If a reasonable model of “A” does not involve some variable “X”, the correct conclusion is that X is not necessary for A. (It is still possible that X is sufficient for A, but the model shows it is not necessary.) As an analogy, modern mathematical models of light do not have a variable for “density of ether”. Does this mean that the modern theory says nothing about a possible connection between light and ether? Of course not. It says that ether is not necessary for light to travel. On the other hand, some waves do require “ether”, e.g., ocean waves. There are lots of ways you can get a wave phenomenon, and likewise, there are lots of ways you can get the cooperation phenomenon. Relatedness is *not necessary* for the evolution of cooperation. In some (perhaps many) cases it is probably sufficient, like parental care of offspring.
It seems to me that Ed Wilson, who understands eusociality as well or better than anybody, is saying that the phenomenon typically evolves for reasons other than kin selection. Nowak, and Tarnita devise a mathematical model with no “kin variables” that leads to something like eusociality. (I doubt Wilson had any say in the mathematics.) Conclusion: kin selection is unnecessary for the evolution of eusociality. Their logic is sound. What really happened on planet Earth in the case of ants, mole rats, etc, remains an open question. I’ll trust Wilson intuition on these matters. The kin selection mathematics is *not* conclusive by any stretch of the imagination.
It seems to me it is you who’s quite confused here about interpretation of mathematical models.
You conclude that kin selection is not necessary for the evolution of eusociality because there are no “kin variables” in Nowak et al.’s model.
You seem to have overlooked the fact that there is in fact a relatedness of 1/2 between offspring of the same mother in the model, since the mother mates only once in the model.
If Nowak et al. had allowed female mating rate (or any other parameter that affects relatedness) to vary in their model, all else being equal, they would have found that eusociality evolves more easily when females mate only once (when relatedness between offspring is highest). Exactly as predicted by kin selection models.
I’m not sure how you would tinker with the model to account for relatedness, but that’s not the issue. The model shows that kin effects are not *necessary*. It’s possible that kin effects could speed things up, but so could a watchful “ceiling cat”. The point is that those are unnecessary assumptions. What really happened in the real world remains an open question.
Relatedness is built into the model already, so kin selection would already seem to be part of the model. But the IMPORTANCE of kin selection isn’t being studied because that variable is held constant.
As Prof. Coyne points out, parental care for young is simply the most obvious manifestation of kin selection, and it occurs in many species whose parents are each 50% related to each child.
Please see my post below. I’m curious how your argument would get around the fact that, assuming eusociality arises through mutation, the original spread of eusociality through a population is equivalent to the relative reproductive success of the kin group in which the mutation arose.
Well, at least this gets a layman confused on the use of mathematical models. I have access to the supplement, and with a short browsing it seems to me that:
The toy model used to distinguish between two strategies does involve relationship through inheritance and it specifically does not exclude specific relationship mechanisms between the strategies. That is the whole point of the supplement first part, they say their theory is (at least) as good as the traditional! It therefore doesn’t seem to embody a test for or against kinship mechanisms.
I am as keen as anybody to use testing. Therefore I want to distinguish carefully between actual tests and purported tests.
Isn’t that a bit specious, since it is an implicit point under the current debate?
Oops. “they say their theory is (at least) as good as the traditional” on that basis (too).
I have one quibble. I don’t think it’s necessarily correct to say that most animals don’t maintain a memory of interpersonal interactions. I know vampire bats track who fails to reciprocate blood sharing, and pretty much any animal that lives in a group has at least a notion of pecking order.
In general, I think people who espouse group selection are missing the trees for the forest. It’s like a huge swarm of birds, where it seems there must be some higher-level direction going on, but there manifestly isn’t.
Neither of your examples have anything to do with kin selection or group selection. Reciprocal altruism and pecking orders are behaviors that could evolve in a number of ways, and once they are established, kinship is only marginally relevant.
Group selection has nothing to do with “higher-level direction”. It’s a physical process, just like individual-level selection. The key is to understand the group-level birth and death processes (fissioning and extinction) going on. When a group fissions, spawning new (offspring) groups, the new groups will “inherit” certain traits of the parent group with variation, like “fraction of cooperators”. Groups with different sizes and compositions have different death rates. This correlation between parent and offspring groups and differential death rates is enough for things like cooperation to evolve. Check out recent theoretical work in this area!
I think you (and many others) think that DS Wilson and his supporters carry the flag for group selection. In fact, their vision of group selection appears to be “equivalent” in some vague sense to kin selection, so there is nothing very interesting going on there.
(subscribing)
“it’s simply two guys and a woman deeply misunderstanding evolution and trying to parlay this misunderstanding into fame.”
I think the second part of this sentence is unwarranted (while the first probably is). Do you really think Nowak and Wilson need more fame? They’re giants already.
As for Ms Tarnita, I wish people here and elsewhere had the good grace to leave her out of it. Yes, she did co-author this paper and does not strictly speaking deserve special protection, but she’s a very young scientist and probably not yet at the level where she can properly evaluate here advisor’s influence on her work.
I absolutely think that Wilson and Nowak WANT more fame. If you think that being famous already in science immunizes you against further ambition, you need to get out more. The same theory about Wilson and Nowak has been broached to me by some of their closest colleagues–people who have worked with them.
And Tarnita is, like all the authors, absolutely responsible for the paper. If she can’t evaluate the historical context and meaning of her work, she has no business putting her name on the paper.
I certainly do need to get out more, even though I would rather learn about the state and pressures of fame from own experience one day 🙂
Still, I am inclined to believe that Nowak et al. are simply misguided and looking for shortcuts rather than consciously misrepresenting existing work (and I am not saying you said that). Your argument from unnamed sources has little value to me, I’m afraid.
And yes, Tarnita is one of the authors and is responsible, I acknowledged as much. I just hoped people would recognise that there are degrees to such responsibility, and that most of it lies undoubtedly with Nowak and Wilson.
I just finished The Selfish Gene, and I have to say, I don’t understand Wilson’s point.
If eusociality is an evolved behavior, then it must have started at some point as the result of a mutation among a population of formerly non-eusocial organisms. If it started as a mutation in one or a few organisms and then spread through an entire population, then it must have done so through kin selection, right? Only organisms that are kin to the first organism to express the mutation will have it at first, and any organism that ultimately has it must be kin to the first organism that has it.
The other alternative is that the mutant organisms would engage in eusociality with other organisms in the population that don’t have the eusocial genes, but it seems as though in that situation, the non-eusocial organisms get the best of both worlds: a free lunch from the eusocial without the need for reciprocation. Unless eusocials already dominated the population, they would be exploited and driven to extinction. For this not to happen, the eusocials must restrict their altruism to other eusocials, i.e. other members of the kin group in which the mutation for eusociality occurred in the first place.
We can talk about group selection somewhere in there: perhaps there are several populations of this particular organism that don’t interbreed very much, and the one population that becomes eusocial is more successful than the other populations, eventually driving them to extinction. But that first population would have acquired eusociality through kin selection whether or not this scenario ever came about.
I think I see your point. (actually, the point you made to my post above). Correct me if I’m wrong. You want to construct a model analogous to the one in section 11 of the “supplementary information” for Nowak et.al., where the organisms have a different kind of genetics? That is clearly quite possible – perhaps tedious. Are you volunteering? But then what? Presumably there will be a different range of “q” values that lead to eusociality. What would that mean?
By the way, I can’t go along with your notion of “evolving by kin selection”. By your usage of the term, I don’t see an alternative to it in any situation. Whenever there is a mutation that spreads because it is advantageous, the result will be a population made up of the mutant’s descendents. What would you consider a case of evolution that was not kin selection?
Cases of evolution that are not kin selection:
camouflage — It doesn’t spread through a population because it causes organisms to altruistically invest in other organisms, it spreads through a population because bearers of a camouflage gene are less likely to get eaten.
sexual selection — spreads because it makes the organism more likely to mate, not more likely to care for kin
The important thing about non-kin selection is that in all cases it increases the relative fitness of genes. That’s what’s so special about altruism and why we need something like kin selection in the first place. Genes for altruism sabotage themselves by causing the bearer to “voluntarily” give up time and energy that could have been spent propagating those genes.
The only way to spread genes for altruism, then, is to make sure that the recipients of the altruistic behavior also bear the genes. This could happen in two ways:
1) The gene is already widespread in the population. But this isn’t the case here, since we’re trying to explain how altruism gets a foothold in a non-altruistic population in the first place.
2) The altruistic organism has some way of determining which other organisms share the genes for altruism (so that the time and energy expended by the parent DO increase the fitness of the gene, just in other bodies). The simplest way to do this is probably to just care for children and maybe siblings, each of which is 50% related to the carer.
If the altruistic organism isn’t choosy as described in (2), then the altruism genes cause it to expend time and energy caring for organisms that don’t share the altruism gene, which makes those genes “less fit” than genes for not being altruistic.
So I can’t help but think you’re misinterpreting what I mean by “kin selection” somewhere; it’s not that the SOURCE of the genes is kin (which is obvious, the source of all your genes are always kin). It’s that the EFFECT of the genes is to behave altruistically towards other organisms that share those genes, and this is most likely going to occur in kin groups.
And I never said anything about constructing another model, I’m just saying I don’t understand even in outline form how Wilson and Nowak’s model could work (without at least accidentally modeling kin selection).
Alright, I figured that you didn’t mean to include everything as kin selection! I think there is something that we agree on:
“The only way to spread genes for altruism, then, is to make sure that the recipients of the altruistic behavior also bear the genes.”
Actually, it doesn’t have to be all or nothing – as long as altruists on the average interact with altruists more often than non-altruists do. This is “assortment”, e.g., Fletcher and Doebeli (2009). The important question is what mechanisms lead to the kind of assortment that allows altruism to flourish.
I think Ed Wilson is arguing that it is protecting the nest that causes the assortment that leads to eusociality, and (of course) the resulting nest will be full of relatives. The dynamical equations in Nowak’s model do not involve kin variables, so I can’t understand why you think kin effects are causal in that model. Perhaps they “go along for the ride”, which is what I think Wilson is saying. I do see what you are trying to argue, though, and I can’t think of a killer reply to it in the case of eusociality. On the other hand, Fletcher and Doebeli have some thought experiments in their paper that demolish the idea that the only way altruism can evolve in general is by kin selection.
One more thing. Nowak et al seem to consider kin selection to be a particular mathematical model. (I’m not sure which one – perhaps the one in “how to make a kin selection model” by Taylor and Frank? I don’t understand why they think “weak selection” is such a big deal.) Anyway, if Hamilton’s rule always works in kin selection models, then Nowak’s dynamical model is not a kin selection model. Try deriving Hamilton’s equation for it! You probably don’t think this is a valid argument, though.
This is confusing too. I see the supplement deriving Hamiltons’ rule in an effort to imply it almost never holds. But so what, why would we need the rule to be an exclusive outcome of the model, embedded in its topology if you will? It should be enough that it holds in some cases for the effect to be real.
Again not a test against, whether or not it was implied as one, but a successful test if anything. (Depends on the parameter space, obviously.)
It’s funny – I was warned when I started working on the evolution of cooperation that discussions like this were inevitable! I think the problem is that there are too many ways the term “kin selection” is used. Nowak thinks kin selection is some particular mathematical model that requires “weak selection”, etc, etc. Others (the majority on this website) see it as a generic name for the evolution of cooperation, so they are equivalent by definition.
In this view, even if a model makes no use of kin or relatedness variables, it’s still a model of kin selection because family groups live together, or because relatives live near each other (even if there’s no space variables!), or some such argument. There’s something unseemly in this line of reasoning, but I’m not a philosopher and I can’t put my finger on it. It reminds me of “apologetics” in a way, although that’s probably too harsh. If a model doesn’t involve a variable, then that variable is not important in the model. Occam’s razor.
Others (the majority on this website) see it as a generic name for the evolution of cooperation, so they are equivalent by definition.
No, I’m using “kin selection” to indicate specifically selection for caring for kin.
There’s nothing unseemly about it. I’m just assuming that the population doesn’t start out with genes for altruism (for obvious reasons) so that “blind altruism,” just helping anyone you meet, is very unlikely to be beneficial and very likely to be harmful.
One obvious exception would be if the altruism is targeted only towards kin. In this case, we’re talking about kin selection. There may be other exceptions, but you have (or anyone else) has yet to explicate one that seems even remotely plausible.
If a model doesn’t involve a variable, then that variable is not important in the model. Occam’s razor.
Occam’s razor requires actually comparing your model to reality. You’re just comparing the model to the model.
First of all, I’m not at all familiar with the mathematics behind these models. I’m much more interested in the ideas that we’re trying to quantify in the first place, which is why I wish Nowak would condescend to explain his hypothesis in plain English rather than gibber about how everything is math (I knew a few annoying kids in college who did the same thing).
Actually, it doesn’t have to be all or nothing – as long as altruists on the average interact with altruists more often than non-altruists do.
This is the crux of my objection right here. If we’re talking about the origin of eusociality or any other kind of altruistic behavior, I don’t see how we can start the game with the trait already widespread enough in the population so that the condition you mention is satisfied. That feels like cheating to me.
The dynamical equations in Nowak’s model do not involve kin variables, so I can’t understand why you think kin effects are causal in that model.
If it’s a selection model, presumably it must include relatedness and inheritance somehow. Are you telling me that in Nowak’s model the children are completely unrelated to the parents, or what? I’m not sure how to make sense of what you’re saying here.
If the children in the model are related to the parents, then I would think we would have exactly the situation in which kin selection is “coming along for the ride,” but I find that phrasing misleading, because I would guess that the relatedness between parents and children is actually doing the heavy lifting in spreading around the altruism trait. Unless it’s spread around as an initial condition, which as I said, would strike me as cheating.
I’m fully willing to admit I may be missing something, but someone would have to explain what it is clearly in English because I really don’t have the background knowledge to be able to judge the model on its own terms. If you could give a sense of how you think it works (again, in plain English) that might be a start.
“No, I’m using “kin selection” to indicate specifically selection for caring for kin.”
What are kin? Any definition you give me for kin, I’ll come up with a model that isn’t kin selection by your definition, but still leads to cooperation. Then you’ll come up with a more general definition of kin, and I’ll come up with another example, etc., etc. Let’s not start!For example, suppose a cooperative mutation emerges twice in the same population by different genes, and you switch the families so the offspring are always with the wrong parents. Is this still kin selection? This is silly, of course, but there are other ways that things can get messy that are more natural, like group fissioning, fusion, and other group-level events.
Anyway, in a realistic (i.e., messy) model it is nearly impossible to keep track of who’s related to who. The kin selection models I’ve seen don’t even try. They usually skip the dynamics and solve for some sort of equilibrium. (I’ll keep my opinion of that tactic to myself.) So another tactic (much better imho) is to forget about relatedness and just write down the dynamical equation for population levels of different organism types. This is what Nowak and Tarnita did.
In this way it’s no different from simple “preditor-prey” population models. Relatedness is not a variable. It’s not what the model is about.
This is silly, of course, but there are other ways that things can get messy that are more natural, like group fissioning, fusion, and other group-level events.
It is incredibly silly, and I have a lot of trouble seeing how “group-level events” could possibly be causally prior to individual level events. In addition, this post doesn’t really address any of the questions I’ve asked.
Let me clarify something, though: I don’t think that kin selection actually involves organisms sequencing each others’ genomes to determine the level of relationship. Rather, organisms rely on signaling systems to determine this, and the signaling systems CAN be gamed.
For example, one species might use, “this creature lives in my nest” as a signal to behave altruistically. In most cases, this is a good proxy for kinship. On the other hand, it’s not perfect as shown by the example of cuckoos.
In the case of your trait arising twice in different events where we then switch the offspring, we’re simply behaving like cuckoos on behalf of each kin group. The question isn’t, “Can human beings cleverly pervert selection effects to reinforce altruism in a population in a manner not describable as kin selection?” The question is “How can altruistic behavior arise in a state of nature?” We and other species can take advantage of the flaws in signaling systems — this is discussed in great detail in TSG — but I still haven’t heard a plausible mechanism for getting such a signaling system started in the first place besides, of course, kin selection.
You don’t need to go anywhere. It comes right up on google! Here it is math.ucdenver.edu/~bsimon/EER%20journal%20version.pdf
Sorry, I didn’t mean to be rude.
We’re talking past each other now. But,
“but I still haven’t heard a plausible mechanism for getting such a signaling system started in the first place besides, of course, kin selection.”
Look at Simon, “a dynamical model of 2-level selection”, Evolutionary Ecology Research (2010), and tell me if you think that is kin selection.
Can you just explain it, or give the gist? I think it’s terribly poor form to demand someone fuck off to the library to follow your argument. Notice I haven’t done that to you.
Alternatively, you can give me a link. I won’t be able to get to the library to look this up, though.
Also, I’m not sure we’re talking past each other. To counter my point about kin selection being pretty much inevitable in any situation with selection for altruism, you said, in essence, “But look, we clever human beings can fool these stupid altruists into helping out non-kin in very contrived, artificial situations!” To which I replied, yes, we clever humans can subvert signaling strategies the same way cuckoos and some species of ants do, but that can’t possibly explain how the organisms got themselves into a position where they can be fooled.
Maybe look at it this way. One of the implicit assumptions behind altruism is it got started with parental investment in children. This is, as several others have pointed out, a straight-forward manifestation of kin selection. Do you think there is another possible origin for altruism besides parental investment in children? If so, please explain.
Sorry, it wasn’t clear to me that the top result was the paper in question.
First impression on skimming it: this is exactly the situation Dawkins describes as “group selection that might actually work” in one of the footnotes to TSG. That is, group selection seems like it might work when it’s bootstrapped by kin selection.
I agree that if you have two isolated groups within a population one of which is dominated by genes for cooperation that the cooperative one might very well outlast the non-cooperative one. The question is how cooperation arose in the cooperative group in the first place.
Basically, this is a more precise statement about what I was saying before about needing a critical mass of cooperators before cooperation pays. This doesn’t need to be so in a global sense, but we do need at least a small region in which it is so. The author seems to assume that we already have this. But that begs the question I’M talking about, which is how we got to critical mass in the first place.
I think you should focus less on the models and more on reality. Your “switched at birth” example is a case in point. Sure, we can cook up some bizarre model in which non-related animals independently mutate cooperative behavior and then completely coincidentally help each other instead of their own kin, but how is that likely to reflect reality? If your model isn’t likely to reflect reality, then you’re doing something wrong.
I see this particular model as being realistic enough, but I also don’t see it as contradicting kin selection. Again, how besides kin selection does any particular group get to a critical mass of cooperation?
“this is exactly the situation Dawkins describes as “group selection that might actually work” in one of the footnotes to TSG.”
Thanks for that lead. I’ll have to check it out.
“I see this particular model as being realistic enough, but I also don’t see it as contradicting kin selection. Again, how besides kin selection does any particular group get to a critical mass of cooperation?”
Notice that in every group, defectors are always gaining on cooperators. So no group gets to a “critical mass” by individual-level population dynamics. The movement is always in the opposite direction. The dynamics that lead to cooperation are at the group level. When a group fissions, some pieces have higher fractions of cooperators than others. Think of a “mutation” at the group level as a fissioned piece that has a significantly different fraction of cooperators than the parent group. So, a small population of cooperators that emerge in some group by mutation and subsequent (asexual) reproduction can potentially make up a sizable fraction of a fissioned piece, (a “mutation”) and then the small piece grows.
If you set the rates that group-level event occur to zero then cooperation can’t establish itself. If you turn them on (at appropriate levels) cooperation establishes itself at some fraction of the total population. So it’s group selection that sustains cooperation in the model. I think you’re going to say that the members of every group are related, so whatever happens, it must be due to that fact. And I will counter that since kin variables have no role in the dynamics, the kin structure is just going along for the ride. How does this resolve itself?
I think you’re going to say that the members of every group are related, so whatever happens, it must be due to that fact.
No, I’m going to ask you what the following actually means:
If you set the rates that group-level event occur to zero then cooperation can’t establish itself. If you turn them on (at appropriate levels) cooperation establishes itself at some fraction of the total population.
What CAUSES group level events? The model takes the occurrence of group-level events for granted, but this is because it is a model, and like all models has limits to its granularity.
In other words, what REAL-WORLD conditions must pertain for group-level events to occur at all?
You say above that if we ASSUME group-level events occur at a particular rate (and write this into the model) then group selection is guaranteed.
I am saying that I am pretty sure that the group-level events are themselves caused by kin selection. After you’ve bootstrapped these group-level events, I 100% agree that you can make group selection work. But not without kin selection working first at a lower level. Is this making more sense?
By the way, this is what I was getting at earlier when I said “I’m having trouble seeing how group-level events could be causally prior to events at the individual level.”
Groups of chimps fission, so do hunter-gather tribes, and other groups of mammals. There are a few references in the paper, but I don’t think that is controvertial. I’ve mostly looked into models of hunter-gatherers. There are lots of ways you could get a fissioning event. A hunting party could get lost and never return to the tribe, or a few individuals get banished. In a model of virulence, the groups are the parasites inside host bodies. When I sneeze, that’s a fissioning event. It seems to me that these have nothing directly to do with kin selection. What’s your take?
The fissioning rate for a hunter-gatherer tribe might be proportional to its size, or something like that. The extinction rate might be proportional to the number of tribes in the environment, or something like that. It’s up to the modeler to choose these things. Then you solve the dynamical equations numerically to see what happens.
“like saying Chardonnay is not wine”
Actually, chardonnay is not wine. It is a variety of grape.
That is funny, since it seems to encapsulate the debate: I believe a Chardonnay is the term for a type of wine.
Encapsulate (some of) the debate, not the nuanced science in it, I haste to add.
Indeed it is. That is one of the stranger remarks I’ve heard on this website. I’ve bought and ordered Chardonnay all my adult life, and I’ve never yet gotten a bottle full of grapes!
You advance the rhetorical observation “Why do Ma and Pa Eagle stay at home and tend the eaglets until they fledge? Why don’t they just go off and build another nest? The reason, of course, is because each parent is related by half ….”
Then please explain, in the presumed illumination of your narrow calculus, the human proclivity to adopt unrelated children (of different races and nationalities).
I don’t suggest that “kin selection is dead” except as a sophomoric argument, but that some more fundamental dynamic determines these phenomena.