Group selection vs kin selection: evidence from examples

Modern versions of kin selection and group selection have turned out to be essentially equivalent. However, historical examples of his selection and group selection have covered some rather different territory. Group selection enthusiasts have chosen phenomena such as senescence and warning signals. From the perspective of kin selection, some of the most obvious examples include breast feeding, parental care and nepotism. The kin selection examples are good, but the group selection ones are more dubious. I've previously argued that the reason group selection was associated with dodgy examples is because advocates sought to distinguish their theory from kin selection - and so avoided examples where it was obvious that kin selection was responsible. The details are in my 2104 article "How kin selection pushed group selection into the scientific fringes".

I think we are seeing a similar phenomenon with cultural group selection and cultural kin selection. My articles on cultural kin selection are illustrated with examples of where kin selection works on shared memes, rather than shared genes. These examples include uniforms, money and religious brotherhoods and sisterhoods. I think these are real examples of cases where Hamilton's rule applies to memes. However, the cultural group selection examples look rather different. One example often given involves Dinka and Nuer populations in the Sudan. Another example involves monogamous marriage customs. In these cases, a simple explanation is that some memes involved are fitter than other ones. Evidence that the memes involved are deleterious to individuals yet spread through group level reproduction or extinction seems to be completely missing. Maybe these are just bad memes. Cultural group selection seems largely unnecessary.

The tendency of group selection enthusiasts to pick bad examples seems common to both the organic realm and the cultural realm. However the explanation I have previously given for the bad examples in the organic realm does not seem to be applicable to the cultural realm. In the case of cultural evolution, cultural group selection seems to be much better known than cultural kin selection is. So, the idea that cultural group selection was bent out of shape to avoid cultural kin selection does not seem very plausible. Another explanation would seem to be required.

My perception is that the cultural group selection enthusiasts are choosing examples of cases where one group does better than another one for cultural reasons. However, that's not a particularly good way of finding examples of where Hamilton's rule applies. The native Americans did badly as a group recently - but that wasn't really due to kin selection or group selection. Their environment changed rapidly and they failed to adapt quickly. Hamilton's rule isn't terribly relevant in cases like these - even though one group is exterminating another one. This is part of the historical problem with group selection. People see groups apparently exterminating each other and then leap to group selectionist explanations without bothering to properly test them to see if they are plausible.

One possible reply by group selection advocates is that kin selection and group selection don't cover the same ground after all. However, lots of people have held that position over the years, but the evidence for it doesn't seem to be there. If you accept equivalence, I think is is hard to deny the prevalence of bad quality examples of group selection. When was the last time you heard breastfeeding or parental care given as an example of group selection? Never, right? Group selection advocates are not thinking about mother-offspring pairs as "groups" - even though that's where the maths says the effect is strongest. Inferior examples associated with group selection arise in both the cultural and organic realms. My previous argument about how kin selection pushed group selection into the scientific fringes doesn't look as though it is the whole explanation. Maybe group selection is just misleading or confusing.

David Sloane Wilson has doubts; asks for help

People have been trying for decades to find something that group selection predicts that kin selection does not. Now the results are in. The most coherent forms of group selection make no new predictions. They are an alternative accounting technique that makes the same set of predictions that kin selection makes. This is fairly widely acknowledged by most of the parties involved these days. Of course, kin selection has been part of the standard orthodoxy in biology for decades.

However, it seems that David Sloane Wilson still has doubts about this. He doesn't see how to apply kin selection in some cases - and he's publicly asking for help. As far as I can see, David has nothing. One of his three examples is cultural group selection. I replied here.

I'm not sure how much help David will get from other kin selection enthusiasts. Most have been unimpressed with David's attempts to rechristen and take credit for a well-established existing theory. Group selection has a long association with junk science. Kin selection depends on close relatedness to produce adaptations. If you emphasize group membership instead of close relatedness - you include a bunch of cases where there's no close relatedness, and adaptations are not produced. Group selection was pushed by kin selection into the scientific fringes - where it focused on cases not obviously explicable by kin selection - which were mostly cases where the theory didn't actually work. In short, group selection is kin selection's evil twin.

David engages in a bit of a straw man attack on kin selection in his article. He focuses on Hamilton's rule. Hamilton's rule is one of the findings by kin selection theorists - but it isn't the same thing as kin selection. Here's how Hamilton explained the topic:

The existence of altruism in nature can be explained by thinking about the replication of genes. We need to descend to the level of the gene, rather than the individual, in order to see that the gene exists surrounded by copies of identical genes that exist in all its relatives - in particular in its close relatives, its siblings, who have a half chance of carrying a copy of that particular gene, its offspring, which also have a half chance, parents: a half-chance, cousins: one eighth, etc. Seeing this swarm of genes that exists around a particular one, we can then ask what is the behavior caused by this gene that is most likely to cause the propagation of this set of copies in the relatives around it.

That is more like kin selection in a nutshell. Of course, these days, we have to clarify that it's the evolutionary gene that we mean here. Hamilton's rule is the product of kin selection and a bunch of assumptions.

Cultural group selection - bibliography

I have previously posted bibliographies of cultural kin selection and the closely-related topic of tag-based cooperation. However some academics have been studying the same topic under a different name and using different models and approaches.

Most bibliographies of cultural group selection seem to be in pre-internet document formats: devoid of links. Here's an HTML linkified one:

• Andre, J.B. and Morin, O. (2011) Questioning the cultural evolution of altruism.
• Bell, Adrianm Richerson, Peter J. and McElreath, Richard (2009) Culture rather than genes provides greater scope for the evolution of large-scale human prosociality.
• Boyd, R. and Richerson, Peter J. (2010) Transmission coupling mechanisms: cultural group selection.
• Boyd, R., Richerson, Peter J. (2002) Group beneficial norms can spread rapidly in a structured population.
• Boyd, R., Richerson, Peter J. (2009) Culture and the evolution of human cooperation.
• Boyd, R. & Richerson, Peter J. (1985) Culture and the Evolutionary Process.
• Cullen, Ben R. S. (1995) On Cultural Group Selection.
• De Smedt, Johan and De Cruz, Helen (2012) Human Artistic Behaviour: Adaptation, Byproduct, or Cultural Group Selection?
• Efferson, Charles, Rafael Lalive, and Ernst Fehr (2008) The coevolution of cultural groups and ingroup favoritism.
• Henrich, Joseph (2004) Cultural group selection, coevolutionary processes and large-scale cooperation (preprint).
• Henrich, Joseph and Boyd, R. (1998) The Evolution of Conformist Transmission and the Emergence of Between-Group Differences
• Molleman, L., Quinones, A.E. & Weissing, F.J. (2013) Cultural evolution of cooperation: the interplay between forms of social learning and group selection
• Richerson, Peter J. & Boyd, R. (1990) Group selection among alternative evolutionarily stable strategies.
• Richerson, Peter J. & Boyd, R. (1999) The evolutionary dynamics of a crude super organism.
• Richerson, Peter J. & Boyd, R. (2008) Solving the Puzzle of Human Cooperation
• Soltis, J., Boyd, R., Richerson, Peter J. (1995) Can group-functional behaviors evolve by cultural group selection? An empirical test.
• Steele, D. R. Hayek's Theory of Cultural Group Selection.
• Zimmerman, Matt, McElreath, Richard and Richerson, Peter J. (2012) Evolution of Cooperation.

How kin selection pushed group selection into the scientific fringes

Group selection lost out to kin selection in the 1960s and 1970s as an explanation for cooperative behaviour. Group selection went on to lead an underground existence - in which a few remaining proponents sought out ways to find things which group selection explained which kin selection did not.

We now know that modern versions of these theories make the same predictions. So there isn't really anything that group selection can explain that kin selection cannot. However this didn't stop the group selection proponents from trying to find these types of phenomena. Indeed, if they had succeeded, fame and glory would have awaited them.

This quest took group selection to the borderlands of science. Kin selection was uncontroversially used to explain obvious adaptations - such as breast feeding, parental care and nepotism. Group selection picked more controversial targets - senescence, the maintenance of sexual recombination and cultural evolution. The theme of these topics seems to have been avoiding rapid refutation of: "kin selection explains that without invoking group selection".

This quest now seems to be mostly over. Most of the group selection enthusiasts have publicly given up their original quest - and have accepted the equivalence between kin selection and group selection.

However the topics group selection is invoked to explain still seem to be skewed away from those that kin selection is used to explain. As a result, group selection is generally offered as an explanation in areas where the theory doesn't function well. This seems like a hangover which group selection is still recovering from.

Group selection enthusiasm still rampant in the social sciences

Most evolutionary biologists got over group selection back in the 1970s. However, there's one area of biology where it is particularly prominent: the social social sciences. There's particular enthusiasm for cultural group selection - as though cultural evolution plays by different rules in this area.

Cultural kin selection represents an alternative perspective which makes little mention of selection acting on groups. Instead of humans being part of innumerable overlapping groups, their genes and memes are modeled as being related to the genes and memes of others. This perspective has been much more enlightening in the organic realm, and I think it will prove to be much more enlightening in the cultural realm as well. The largely-fictional groups of group selection are just a clumsy and awkward way of viewing the situation - most of the time. The perspective has a long history of producing dud science.

In most of evolutionary biology, 90% of scientists are using kin selection and 10% are using group selection. In the social sciences, it's the other way around. I think that this fairly clearly indicates the existence of a problem.

Why is group selection still so popular among social scientists? For a long time many of them held out hope that it would prove to be a new theory of social behaviour. These hopes now appear to have been crushed by the failure of the theory to make different predictions from the long-established orthodoxy of kin selection.

Social scientists have a long history of not understanding how evolutionary biology applied to their subject areas. As a result there's a large scientific lag afflicting the study of cultural evolution. Group selection enthusiasm seems to be clearly one aspect of that: the numerous social scientists involved are stuck back in the 1960s somewhere, where the virtues of the kin selection perspective were not yet widely appreciated.

Lastly, group selection in the social sciences seems to have found extensive funding from the John Templeton Foundation. In a surreal twist to the final battle between science and religion, group selection enthusiasm has been funded to the tune of millions of dollars. That kind of marketing budget can buy a considerable quantity of confusion.

Obvious types of kin selection

If you ask a student of kin selection about the most obvious aspects of the human phenotype that have been influenced by kin selection and are coded for in human DNA, I think you would generally get back a list looking something like this:

• Genitals;
• Breasts;
• Placenta;
• Umbilical cord;
• Female body fat;
• Maternal love;

If you ask a group selection proponent the corresponding question (what are the most obvious aspects of the human phenotype that have been influenced by group selection and are coded for in human DNA), I think you would get back a very different list. The group selection proponent might be more likely to mention multi-cellularity - but I think they would be highly likely to back a very different list.

What's up here? Kin selection and group selection are basically the same thing.

I don't pretend to have a complete explanation for this - but I think the group selection enthusiasts were led astray by the urge to distinguish themselves from kin selection enthusiasts. If discussing family groups, it was obvious that kin selection applied to it - and explained it. The group selection advocates therefore focused their attention elsewhere - where it seemed as though there was more chance to explain new phenomena that kin selection failed to cover. This hypothesis explains the migration of group selection enthusiasts to cultural evolution - since that is obviously not down to shared DNA.

Eventually, there was nowhere else to run, and the group selection advocates mostly gave up their claims that group selection was something new and different. Now the rhetoric in the area has mostly shifted to other issues.

Why the kin vs group selection arguments persist

There have been a few attempts to explain the persistence of the clash between kin selection and group selection enthusiasts, beyond the recognition of the broad equivalence of the approaches.

D. S. Wilson wrote Clash of Paradigms: Why Proponents of Multilevel Selection Theory and Inclusive Fitness Theory Sometimes (But Not Always) Misunderstand Each Other.

Recently Herbert Gintis has offered his perspective in a review of the book Evolutionary Restraints: The Contentious History of Group Selection.

It seems to me that much of the apparent disagreement comes from those on the outskirts of the debate, who don't properly understand it. The last couple of years has seen a number of confused articles - from Steven Pinker, Edward Wilson, Martin Nowak and others - who just don't know what they are talking about.

Part of the disagreement comes from inertia. People get taught one technique and then get attached to it - and are reluctant to use the other 'unnecessary' approach.

I also think this is partly a conservative vs revolutionary issue. Kin selection is the establishment, group selection is the rebel. Kin selection is tried and trusted, group selection is new and disruptive. Theories with these traits appear to different personality types.

There's also the issue of 'selfishness'. Group selection pictures groups that nurture cooperation flourishing at the expense of groups of selfish individuals. Kin selection seems to be promoting a picture of gene level selfishness. This picture is factually false (the reality doesn't change depending on how you look at it) but the connotations are there. Some like to publicly signal their unselfishness via their beliefs. To others, such cheap signalling seems more like tasteless self-promotion.

Lastly there's confusion over cultural evolution. Most of the group selection enthusiasts come from the social sciences. I've repeatedly heard them argue that kin selection only applies to genetic relatives, and that human cooperation extends beyond blood kin - so there must be something else going on. This argument ignores the important topic of cultural kin selection. The "something else" that is going on turns out to be kin selection after all.

Since kin vs group selection seems closely tied to political and moral issues, perhaps we won't see much more agreement on the topic anytime soon.

Nowak nominates inclusive fitness for retirement

The 2014 annual question at The Edge is: What scientific idea is ready for retirement?

Martin Nowak nominated inclusive fitness. He writes:

Contrary to what is often claimed there exists no empirical test of inclusive fitness theory; nobody has ever performed an actual inclusive fitness calculation for a real population. Inclusive fitness was originally understood as a crude heuristic that can guide intuition in some cases, but not in general. It is only in recent years that inclusive fitness has been elevated—mostly by mediocre theoreticians — to a religious belief, which is universal, unconstrained and always true. Understanding the limitations of inclusive fitness gives us now the opportunity to develop mathematical descriptions of key phenomena in social evolution. It is time to abandon inclusive fitness and focus on a meaningful interaction between theory and experiment in sociobiology.

This seems like unsubstantiated scientific FUD to me.

Nowak claims that the:

dominant and unfortunate impact has been the suppression of meaningful mathematical theories in wide areas of sociobiology.

He means group selection? I think this is unreferenced and unsupported nonsense.

From the 1970s onwards we actually understood that evolution does not permit a single quantity that is always maximized. This fact still has to sink in with many in the inclusive fitness community.

I think that the first sentence here is technically mistaken. You can in fact, model the evolution of any dynamical system using the concept of maximisation of a utility function. Take, for example, the utility function that assigns world events that happen utility 1 and world events that do not happen utility 0. In this case, the evolution of the system can be modeled by "a single quantity that is always maximized". This is the fact of the matter. Nowak's proposed 'fact' is a simple falsehood. We didn't understand this 'from the 1970s onward' - it is simply not true in the first place.

Nowak writes:

On the level of genes there is no inclusive fitness.

Really? Most pairs of genes are either copies of each other (r=1) or not (r=0). Plug these numbers into Hamilton's rule and it works fine. This illustrates the meaning of "The Selfish Gene": genes only care about themselves - or copies of themselves. Nowak doesn't explain what the perceived problem is.

More relating to Nowak's article:

• Marczyk, Jesse (2014) Which Ideas Are Ready to Go to Florida?

• Reuell, Peter (2014) Harvard Gazette press release

Why can't we all just get along?

After the 2010 Nowak, Tarnita, & Wilson affair, Samir Okasha weighed in with a comment in Nature, effectively asking: why can't we all just get along?

The paper was titled: Altruism researchers must cooperate. It is indeed ironic that the science of cooperation has led to so much scientific acrimony.

In the paper, Samir embraces equivalence, writing:

kin and multi-level selection are not alternative theories; they simply offer different takes on the question of how social behaviour evolved. Proponents of kin selection, for example, explain sterile workers in insect colonies by saying that the workers are helping the queen to reproduce, and thus boosting their own inclusive fitness. Proponents of multi-level selection argue that the workers are providing a benefit to the colony as a whole, thus making the colony fitter than other colonies. These explanations may seem different, but mathematical models show that they are in fact equivalent

He says the persistent rival camps are a puzzle since:

The existence of equivalent formulations of a theory, or of alternative modelling approaches, does not usually lead to rival camps in science. The Lagrangian and Hamiltonian formulations of classical mechanics, for example, or the wave and matrix formulations of quantum mechanics, tend to be useful for tackling different problems, and physicists switch freely between them.

His explanation:

History shows that, despite its enormous empirical success, evolutionary biology is peculiarly susceptible to controversy and infighting. This is particularly true of social evolution theory, in part because of its potential applications to human behaviour.

I think this is essentially correct. People fight over application of evolutionary theory to humans for many reasons, but among them are: "it's complicated", and "it's important to get it right".

Group selection doesn't score well in the latter category. It isn't so much that it is wrong, it's more that it has led to decades of muddle, confusion and poor-quality science. If kin selection and group selection are feeling different parts of the same elephant, kin selection has hold of the trunk, while group selection is groping the left thigh.

It is certainly frustrating to have all the biology papers using kin selection, while all the humanities papers seem to use group selection.

A big part of the problem is misunderstandings surrounding cultural evolution. Cultural evolution has historically lagged by decades behind conventional evolutionary theory. There was a revolution in the 1970s in which group selection fell out of fashion, and kin selection became much more popular. A parsimonious explanation of the penchant for group selection in the social sciences is that the field of cultural evolution has yet to go through this transition. The significance of relatedness between memes and memeplexes has yet to be fully appreciated.

The productivity of kin selection and group selection

West Griffin and Gardner wrote a comparison of kin selection and group selection, titled: Social semantics: how useful has group selection been?. Thay basically said that kin selection was the hands-down winner.

I think it is hard to argue that group selection has been anywhere near as productive as kin selection. However, group selection enthusiasts have been massively outnumbered over most of the recent history of the two ideas. Group selection defenders can claim that group selection has been less productive due to fewer man-hours expended on it.

The primary strengths of kin selection as I see them:

• Kin selection makes extensive use of relatedness (a concept group selection enthusiasts rarely mention). This facilitates making quantitative predictions.

• Kin selection has "Kin" in its title, which emphasizes the significance of kinship to the effect. Calling the effect "group selection" fails to to emphasize kinship. In practice this leads to applications where kinship isn't involved - and such applications are more often than not errors and mistakes.

• The field is more mature, established and respectable.

I think that group selection appeals more to those who are attracted to the scientific fringes - in the hope of finding useful things there. That's all very well, but the the scientific fringes have a lot of junk science in them as well. Some of it is to do with group selection. Take care with it.

Productive chickens: group selection vs kin selection

Group selection advocates often cite laboratory studies on breeding chickens to maximise egg production.

What they don't mention is that the birds involved were housed by sire family, were close relatives - and the whole process was conceived at the time in terms of kin selection. Check out this quote:

Craig (1982) advocated kin selection, in which pullets are housed in cages together as families with mean performance used as the criterion of selection. He hypothesized that families that perform best tend to have those physiological and behavioral characteristics most appropriate for group well-being and productivity. Muir (1985), Craig and Muir (1993), and Muir (1994) hypothesized that kin selection would favor cooperative tolerant behavior and concluded that selection on family means, when families are kept together as family groups, provides a method of improving traits in which behavioral interactions influence overall well-being and productivity.

The challenge for group selection has always been distinguishing itself from its widely-accepted rival, kin selection. The case of the chickens surely represents a failure to do this.

References

• Muir, W. M. and Crig, J. V. (1998) Improving Animal Well-Being Through Genetic Selection

Tree trunks are not wasteful selfishness

I re-read the Dawkins essay "Gods Utility Function" recently. Dawkins offers an argument against high-level selection in it. However, the article gives a string of dodgy examples. He argues that tree trunks are wasteful:

Why are forest trees so tall? Simply to overtop rival trees. A “sensible” utility function would see to it that they were all short. They would get exactly the same amount of sunlight, with far less expenditure on thick trucks and massive supporting buttresses. But if they were all short, natural selection couldn’t help favoring a variant individual that grew a little taller. The ante having been upped, others would have to follow suit. Nothing can stop the whole game escalating until all trees are ludicrously and wastefully tall. It is ludicrous and wasteful only from the point of view of a rational economic planner thinking in terms of maximizing efficiency. But it all makes sense once you understand the true utility function-genes are maximizing their own survival.

This is wrong. Very tall tree trunks are found in the most efficient dissipating regions of the earth: rain forests. These extract far more energy from incident sunlight that the grasslands that resemble the type of ecosystem which Dawkins is describing as more efficient. Those tree trunks pay off in efficiency terms. If you have a flat surface, it heats up - and the incident energy radiates back into space. You need a lot of surface area to allow water evaporation to keep you cool. The depth produced by tall trees helps to provides such a surface.

In the essay, Dawkins also describes elephant seal sex ratios as "inefficient":

The sex ratio-the proportion of males to females-in wild populations is usually 50:50. This seems to make no economic sense in those many species in which a minority of males has an unfair monopoly of the females: the harem system. In one well-studied population of elephant seals, 4 percent of the males accounted for 88 percent of all the copulations. Never mind that God’s Utility Function in this case seems so unfair for the bachelor majority. What is worse, a cost-cutting, efficiency-minded deity would be bound to spot that the deprived 96 percent are consuming half the population’s food resources (actually more than half, because adult male elephant seals are much bigger than females). The surplus bachelors do nothing except wait for an opportunity to displace one of the lucky 4 percent of harem masters. How can the existence of these unconscionable bachelor herds possibly be justified? Any utility function that paid even a little attention to the economic efficiency of the community would dispense with the bachelors. Instead, there would be just enough males born to fertilize the females.

Unfortunately for this argument, the surplus of males helps the population weed out parasite-ridden and mutation-loaded individuals. A population with fewer males would mean males of lower quality breeding - with the quality of individuals cumulatively declining over the generations. Dawkins' economic argument about how the makes are redundant is simply mistaken. The deaths of the failed males helps the population to adapt by marking out the adjacent gene-space that represent reduced quality - helping the population flee from its parasites and decrease its mutational load.

Perhaps it is possible for trees to be too tall - and for there to be too many elephant seal males. However tall trees and numerous male elephant seals proves very little.

Of course, the basic theme of this essay - that "the true utility function of life, that which is being maximized in the natural world, is DNA survival" is hopelessly mistaken.

Dawkins' argument against multi-level selection in this essay is also incoherent.

The problem with cultural group seletion

What do you get when you put two new theories together?

In the case of cultural evolution and group selection, what you seem to get is a big scientific muddle. Let me explain:

Many modern cultural theorists treat culture as a second inheritance channel that affects and modifies human phenotypes (extended phenotypes in the case of artifacts). This is instead of modeling cultural symbionts as separate lineages with distinct phenotypes of their own. For more on this see Against the extended genotype

This perspective has led to multiple claims that group selection is responsible for various features of human culture:

For example monogomous marriage customs and human ultrasociality have both been recently attributed to group selection.

There are two separate problems with this sort of literature:

The first is that typically no evidence is presented to show that these memes are deleterious within groups. If you count the spread of memes that are simply advantageous as a form of "group selection", then all widespread cultural phenomena qualify and the term becomes meaningless. Group selection theorists should try harder to distinguish between group selection and byproduct mutualism - which can both produce "groupish behaviour", but by independent mechanisms. It is true that some individuals benefit from polygamous marriage and anti-social selfishness, but other individuals are harmed, and if the balance is positive, group selection must compete with an obvious explanation: that some individuals are manipulating other ones using memes which have high average fitness and spread by perfectly ordinary natural selection.

The second problem is that - just because you can model a phenomena using multi-level selection and the Price equation, it doesn't mean that it makes sense to do so. Rather than observing that selection on human hosts and selection on memes operates on different scales - and reaching for the multi-level selection toolkit - what should happen is that the fact that humans and their memes are not geneaologically related should be noted, and they should be modeled as independent species using natural selection on humans and natural selection on memes. Multi-level selection is an unnecessary and confusing complication in such cases.

To illustrate, compare with the case of the smallpox virus. Smallpox germs wiped out many native Americans. The smallpox scabs are an aspect of individual human phenotypes. They are deleterious to individual humans (they kill people). However has historically been advantageous to human *groups* to have the smallpox phenotype - since this trait obliterated many competing tribes of humans (e.g. see American history). I think that few would advocate multi-level selection modeling in this case. There are two distinct types of entity involved here: humans and the smallpox virus. Natural selection operates on them more-or-less independently. Group selection brings no enlightenment and much confusion to this situation. The idea that smallpox scabs are traits which spread because they are deleterious to individuals and advantageous to groups is just a misleading and bad way of looking at the situation. It could equally well have been true that smallpox scabs were deleterious to human individuals and human groups - in which case it could still spread for its own "selfish" reasons. Group selection would then have been a red herring in explaining the spread of smallpox.

What holds for smallpox virus scabs holds for many kinds of memes. "Gun" memes result in people dying just as surely as in the case of the smallpox virus. Like smallpox, guns killed many native Americans - and gun memes provide broadly-similar group level advantages. You can model the spread of gun memes using multi-level selection and the Price equation. It is an unenlightening and confusing thing to do, but you can do it.

Its much the same with monogamy memes and cooperative memes. Memes don't interbreed with humans - they are more like separate species. So, you can forget about multi-level selection and just apply ordinary natural selection models to the humans and the memes - and have a much cleaner, neater model. Since human genes and memes are more like different species, it is an unnecessary source of complication and confusion to muddle them together in a unified multi-level selection model - just because they influence the same phenotypic traits sometimes.

It's worth sorting this muddle out - partly because memes exhibit their own kin/group selection dynamics, which can be important and significant. This is where genuine kin sleection/group selection operate in the cultural realm. If "cultural group selection" gets turned into a meaningless catch-all term for cultural phenomena which spread despite being deleterious to human hosts, it risks losing the possibility of performing useful work in other contexts.

References

• Henrich J, Boyd R, & Richerson PJ (2012). The puzzle of monogamous marriage. Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 367 (1589), 657-69 PMID: 22271782
• Peter Turchin, Thomas E. Currie, Edward A. L. Turner, and Sergey Gavrilets (2013) War, space, and the evolution of Old World complex societies
• Johnson, Dominic D.P., Price, Michael E. and Mark Van Vugt (2013) Darwin’s invisible hand: Market competition, evolution and the firm

Clade selection

"Kin selection" and "group selection" are common terms for the way that organisms help organisms which are similar to themselves. I've proposed the term "similarity selection". Another contender is "clade selection". This term came from George C. Williams (1992).

Dawkins said of this:

Williams efficiently disposed of “group selection,” which never recovered (except as a muddled version of kin selection). But in Natural Selection: Domains, Levels and Changes (1992), where he gathered many threads of thought, he developed the important and superficially similar idea (foreshadowed in Adaptation and Natural Selection) of “clade selection” to explain, not “altruism” but macroevolutionary patterns of diversity and - as I would put it - “the evolution of evolvability.”

"Clade selection" seems like better terminology than "group selection" - in some respects. Like the term "kin selection" it puts an explicit emphasis on relatedness. Group selection only works - in the sense of producing group-level adaptations - when relatedness is involved. So: why not use the term clade selection?

Alas, I think there's a good reason not to use the term "clade selection". A clade consists of an organism and all its descendants. The problem is with the "all". You can still have group selection that works without it being clade selection - by the fitness delta involved not affecting all the descendants.

The "all" in "clade" makes "clade selection" a confusing term. Not worthless, perhaps, but I don't think I can endorse the term.

Kin selection's vs the John Templeton Foundation

Is it true that kin selection's opponents are funded by the Templeton Foundation?

Jerry Coyne alleges this:

Finally, much of the work on group selection has been funded by the John Templeton Foundation, an enormously wealthy organization with an agenda to harmonize faith and science. The idea of group selection, with its spiritual and religious connotations—the process is often used to explain the prevalence of religion and societal harmony—is right up their alley. So the proponents of group selection monopolize not only the megaphones but the funding. In science, money talks.

David Sloane Wilson (here), Jonathan Haight (here) and Martin Nowak (here) have all been linked to Templeton foundation funding. The 2010 attack on kin selection by Nowak, Tarnita and Wilson was funded by the Templeton foundation. They funded SuperCooperators, The Happiness Hypothesis and Darwin's Cathedral.

Nowak's grant was ten million dollars - we are not talking about peanuts here.

The Templeton Foundation funding puts a strange slant on the issue. It is strange to think that some of the skirmishes in the ancient battle between science and religion are now being shrouded in arcane mathematics and published in top science journals.

Tim Tyler: Williams, Plan and Purpose in Nature (review)

Tim Tyler: Williams, Plan and Purpose in Nature (review)

Transcript:

Hi. I'm Tim Tyler, and this is a review of this book:

Plan and Purpose in Nature: The Limits of Darwinian Evolution by George C Williams.

George Williams is an expert in Darwinian evolution, and this book is an attempt to condense his knowledge down into a format which is easily digested by those new to the field. It is very readable and entertaining book.

It covers basic issues in evolutionary biology, particularly adaptationism, the unit of selection, sexual reproduction, senescence and medicine.

Williams embraces the term "The adaptationist program" - saying he almost selected it as the title of his book. This phrase originated with Gould and Lewontin - and was intended as a term of derision. No doubt Williams is making a point by using the term, but I would have preferred that adaptation enthusiasts left it alone - making it harder for critics to point at instances of the alleged phenomenon.

The book was published in 1996 - and I thought it was interesting to see what had changed since then. Williams offered an explanation for sexual reproduction that invokes generating diversity to help adapt to novel environments. For example plants like strawberries reproduce using runners and vegetative reproduction locally, but produce sexual seeds for transmission of offspring to a diverse range of remote environments. That is not a completely unreasonable explanation, but the modern way of putting it invokes parasites. If it wasn't for the need to evade parasites, the environment would often not change fast enough to favour sexual recombination. Williams does mention parasites, but they aren't the main feature. Another area where I noticed there were some oddities were in the chapter on senescence. The disposable soma theory and the antagonistic pleiotropy theory of aging are given without being named - and Williams emphasizes how senescence of living bodies is nothing like senescence of machinery - saying:

In thinking of senescence, the analogy to the wear and tear, or corrosion, or other process that ultimately causes an artificial device to fail is utterly misleading.

I think that the relationship here is close enough to not deserve being described as "utterly misleading". Indeed these days we have new modern theories of senescence - like "reliability theory" - that apply to both machinery and bodies, that highlight the relationship between senescence in both kinds of system.

The section about group selection has stood the test of time reasonably well. Williams says that most animal groups are not functionally organized, and that most groups are "just mobs of self-seeking individuals". That's true - though these days people might take more care to mention the possibility of cooperation with kin - i.e. genetic selfishness, not individual selfishness.

The section about medicine is welcome as well. However, while Darwinian medicine sounds nice, we seem firmly embedded in the era of "drug company" medicine, with little sign of an end in sight.

At the end of the book there's a section on philosophical implications. Williams describes the product of natural selection as immoral. He says "although the biological creation process is evil it is also abysmally stupid". His example of the horrors of natural selection is infanticide by males, which he argues is natural and adaptive - though obviously infanticide by males is certainly not adaptive in many modern societies today - since it is likely to result in extended incarceration. Williams endorses Dawkins' proposed rebellion against the selfish replicators and responds to naturalistic moralities with condemnation. This is a common position these days, but human morality sits firmly in the domain of evolutionary theory, and if your theory of evolution doesn't explain it, you need to rethink it. I figure that evolutionary theory offers reasonable explanations of morality that we don't need to apologize for.

Anyway, this is still a fine book - though perhaps some learned readers might find it too simplistic.

Enjoy,

Tim Tyler: Okasha, Evolution and the Levels of Selection

Transcript:

Hi. I'm Tim Tyler, and this is a review of this book:

Evolution and the Levels of Selection by Samir Okasha

I'd previously read Samir's Very Short Introduction to the Philosophy of Science. I thought that was good - and so I had some idea of what this book would be like.

The book contains an interesting and entertaining romp through the territory of group selection. It's what I call a "firehose presentation". In other words, it's a long stream of technical material that doesn't let up. This is a good match for my own preferences in a science book. Samir goes through practically every controversy in the field, and provides insightful opinions and commentary.

The book contains discussions of the Price equation and its significance, causality, emergence, evolutionary transitions, the gene's eye view, species selection, the group selection controversy and kin selection.

I thought the book was interesting and good. However, there were also quite a few parts of it which I disagreed with - or did not like. This is a reflection of the controversial nature of the subject matter.

The book dates from 2006. Throughout most of the history of the field of group selection, many of its advocates considered it to be a super-set of kin selection - often saying things like: relatedness is only one of many ways in which altruists can form groups which are then selected. However in recent years, the quest to find things that group selection explained - and that kin selection did not - seems to have petered out, with many of the most vocal group selection advocates now proclaiming its equivalence to kin selection. Samir's book predates many of these developments - and I suspect anyone writing a book on the subject today would treat the topic rather differently.

The book discusses kin selection only rather briefly. There's a discussion about it in the chapter relating to the group selection controversy, and another one in the chapter about evolutionary transitions. Samir recognises the possibility that kin and group selection might be equivalent, and cites several sources who claim that it is, sometimes approvingly. However, most of this book makes no mention of kin selection.

These days, I think few would approach group selection this way. Kin selection has a rich and successful history, while group selection has spent most of its existence mired in confusion and controversy. Kin selection has been much better studied. So: an obvious approach to many of the topics in this book would be to just use kin selection. However, it is hard to imagine this whole book being written in the language of kin selection. A good number of the issues just seem less important from that perspective. For example, in group selection there's the issue of what counts as a group. This broadly maps onto the issue of what counts as an individual in kin selection - yet this issue seems less controversial. Group selection faces of issue of how to model parly-overlapping groups - since most group selection models feature disjoint groups. Yet the corresponding issue of partly-overlapping families in kin selection seems less contentious. It's hard to escape the impression that the need for this book is partly because group selection is so awkward, difficult to understand and poorly-studied. Since kin selection is much better studied and much more widely used, it seems as though there would be less need for a philosopher to clear up misunderstandings in the field.

Samir offers several digs at the views of Richard Dawkins in the book. He criticises the idea that evolution is based on replicators, offering Hull's comment about them "passing on their structure intact" to claim that the term "replicator" implies high fidelity copying. I think that practically everyone on both sides of this debate agrees that high fidelity copying is not necessary - and it's high fidelity information transfer that matters for cumulative adaptive evolution. No modern users of the term "replicator" in biology use the term in that way - and many of them have objected to this persistent misunderstanding. Of course it's partly Richard Dawkins' fault for assigning an ordinary english word a counter-intuitive technical meaning.

Saimr also criticises the gene's eye view on two grounds. First, he says that it ignores behavioural and environmental inheritance. That isn't true if you adopt an information-theoretic definition of the term "gene" following Williams - since then memes are a type of gene, and the gene's eye view remains valid. Saimr also says that epistasis and "modifier genes" act against the gene's eye view. This is strictly true, but some linearity in the expression of genes is really all that is required to make the gene's eye view useful. Since a linear component in the expression of genes is ubiquitous, this issue seems like a storm in a teacup to me.

Like any complex technical book, there are some mistakes. The most embarrassing one I spotted was where Samir offered an incorrect definition of inclusive fitness - including the "augmenting" but not the "stripping" component - on page 145. Samir's explanations are usually clear - but sometimes the light fades. One such problem comes with the concepts of "MLS1" and "MLS2". Samir introduces these concepts by saying that they represent different focuses of interest on page 56. However on page 59 we hear that "MLS1 and MLS2 are distinct processes" and "whether either occurs in a particular case is a matter of objective fact". At best, this sort of material is very confusing.

Overall, this is a fine book - but I was left wondering if Samir had directed his energies in an appropriate fashion. The book will probably contribute to the modern group selection revival. However that revival seems likely to be accompanied by the usual muddle and confusion that follows group selection around like a black cloud. The problems with group selection at this stage are more sociological than anything else. Yes, groups exhibit reproduction and differential reproductive success, and that affects the course of evolution, but the problem is that practically whenever group selection gets used it results in junk science, or at best, science that is inferior to that which would have been produced by using kin selection. Looking at the mess that group selection has caused in the evolutionary human sciences illustrates this point. Does the world really need more group selection? After reading Samir's book, I was still sceptical. Samir doesn't address sociological questions concerning whether the muddle associated with group selection means that it does more harm than good. Instead, he just wants to clear up the muddle. But in that case: why not use kin selection? It seems much better studied, much less confusing, and has produced much less junk science.

What I think group selection needs most is clearly-articulated reasons to use it in place of kin selection. At the moment, the "why not use kin selection?" question is challenging to answer. Maybe there are reasons - but this book doesn't really provide an answer. It doesn't even ask the question.

Enjoy,

Equivalence naysayers

Not everyone is on board with kin selection and group selection turning out to be the same thing. Some quotes from the naysayers:

The non-equivalence of group selection and kin selection is therefore not only an important finding in itself, but also a case where the use of the Price equation leads to a claim that is not correct.

- Van Veelen M, García J, Sabelis MW, Egas M. (2012) Group selection and inclusive fitness are not equivalent; the Price equation vs. models and statistics.

Moreover, the claim that group selection is kin selection is certainly wrong.

- Nowak, Martin A., Tarnita, Corina E., and Wilson, Edward O. (2010) THE EVOLUTION OF EUSOCIALITY.

The concept of Group Selection has no useful role to play in psychology or social science.

- Pinker, Steven (2012) THE FALSE ALLURE OF GROUP SELECTION

Group selection', even in the rare cases where it is not actually wrong, is a cumbersome, time-wasting, distracting impediment to what would otherwise be a clear and straightforward understanding of what is going on in natural selection.

- Dawkins, Richard (2012) "Group Selection" Is A Cumbersome, Time-Wasting Distraction

He treated kin selection as a special case of group selection, an error which I was later to highlight in my paper on “Twelve Misunderstandings of Kin Selection” as Misunderstanding Number Two. Kin may or may not cling together in a group. Kin selection works whether they do or not.

- Dawkins, Richard (2012) The descent of Edward Wilson

the kin selection model is merely a special case of the multilevel selection theory

- Turchin, Peter (2011) Warfare and the Evolution of Social Complexity: A Multilevel-Selection Approach

Maybe, neither inclusive fitness nor evolutionary game theory can cover all mathematical intricacies of the other approach.

- Arne Traulsen (2009) MATHEMATICS OF KIN- AND GROUP-SELECTION: FORMALLY EQUIVALENT?

Ever since the publication of G. C. Williams' 1966 classic Adaptation and Natural Selection, biologists have joined with social scientists to form an altruism debunkery society. Any human or animal act that appears altruistic has been explained away as selfishness in disguise, linked ultimately to kin selection (genes help copies of themselves), or reciprocal altruism (agents help only to the extent that they can expect a positive return, including to their reputations). But in the last few years there's been a growing acceptance of the fact that "Life is a self-replicating hierarchy of levels," and natural selection operates on multiple levels simultaneously, as Bert Hölldobler and E. O. Wilson put it in their recent book, The Superorganism.

- Jonathan Haidt (2012) Contingent Superorganism

bees, ants and termites did not evolve their social behavior by group selection, but by a different mechanism known as kin selection

- Massimo Pigliucci (2011) Jonathan Haidt does it again, unfortunately

The altruism that evolves by group selection is "genuine" because it entails real self- sacrifice, while the altruism that evolves by kin selection is only "apparent" because it is just genes promoting copies of themselves in other individuals.

- David Sloane Wilson (1994) INTRODUCING GROUP SELECTION TO THE HUMAN BEHAVIORAL SCIENCES

Multilevel selection is gaining in favor among evolutionary biologists because of a recent mathematical proof that kin selection can arise only under special conditions that demonstrably do not exist, and the better fit of multilevel selection to all of the two dozen known animal cases of eusocial evolution.

- E. O. Wilson (2013) The Riddle of the Human Species

To his credit, David Sloane Wilson has subsequently reversed his position on this issue.

However, as of 2015, he still denies that kin selection and group selection cover the same turf. In Challenge To Kin Selectionists. Explain This! he claims that group selection is a more general theory.

Modern kin selection and group selection concepts have turned out to have an enormous overlap. Even if they are not identical, they are certainly very close concepts.

Group selection and kin selection: formally equivalent

These days, there's a scientific consensus about group selection and kin selection.

As Marek Kohn said in 2008:

There is widespread agreement that group selection and kin selection — the post-1960s orthodoxy that identifies shared interests with shared genes — are formally equivalent.

As Michael Wade, 2009 put it:

It is remarkable that kin selection has been widely accepted and group selection widely disparaged when, for simple genetic models, they are actually equivalent mathematically.

As Peter Richerson, 2012 put it:

I think most evolutionists now agree that kin and group selection are the same thing.

Such observations date back to Hamilton (1975). Queller (1992) is another important paper on the topic.

Modern paper titles in the area include: "Group selection and kin selection: two concepts but one process" and "Group selection and kin selection: formally equivalent approaches".

In "Social semantics: how useful has group selection been?", West, Griffin and Gardner (2009) state:

There is no theoretical or empirical example of group selection that cannot be explained with kin selection.

The theoretical equivalence of kin selection models with those of the new group selection seems to be fairly widely recognized. Wilson and Wilson (2007) seem to agree, saying:

The theories that were originally regarded as alternatives, such that one might be right and another wrong, are now seen as equivalent in the sense that they all correctly predict what evolves in the total population. They differ, however, in how they partition selection into component vectors along the way. The frameworks are largely intertranslatable and broadly overlap in the kinds of traits and population structures that they consider.

Formal models of "group selection" and "kin selection" are now widely regarded as producing the same results. Gardner and Grafen (2008) say:

group selection has already been incorporated into social evolution theory, and is found to be exactly equivalent to kin selection: the two approaches are simply different ways of describing the same evolutionary process and both lead to the prediction that individuals should maximize their inclusive fitness

Here's Gardner, West and Wild (2011):

it has long been understood that the kin selection and multilevel (group) selection approaches to social evolution are mathematically equivalent, and merely represent different partitions of the same evolutionary process (i.e. natural selection; Hamilton, 1975; Grafen, 1984, 2006a; Wade, 1985; Frank, 1986, 1995; Queller, 1992b; Rousset, 2004; Gardner et al. , 2007; Lehmann et al., 2007b; Gardner & Grafen, 2009). No model of multilevel selection has ever delivered a (correct) prediction that could not be reformulated in terms of kin selection – despite repeated claims to the contrary.

Kerr and Godfrey-Smith (2002) recommend switching between the two perspectives - saying:

we also argue that each type of model can have heuristic advantages over the other. Indeed, it can be positively useful to engage in a kind of back-and-forth switching between two different perspectives on the evolutionary role of groups. So the position we defend is a “gestalt-switching pluralism.”

Group selection enthusiast Samir Okasha endorsed equivalence in a 2010 editiorial titled Altruism researchers must cooperate writing:

Lastly, kin and multi-level selection are not alternative theories; they simply offer different takes on the question of how social behaviour evolved. Proponents of kin selection, for example, explain sterile workers in insect colonies by saying that the workers are helping the queen to reproduce, and thus boosting their own inclusive fitness. Proponents of multi-level selection argue that the workers are providing a benefit to the colony as a whole, thus making the colony fitter than other colonies. These explanations may seem different, but mathematical models show that they are in fact equivalent.

To his credit, group selection enthusiast David Sloane Wilson is now on the correct side in this debate. So is group selection enthusiast Peter Richerson and group selection enthusiast Michael Wade.

For naysayers in this area, see here.

References

• Marshall, J.A. (2011) Group selection and kin selection: formally equivalent approaches.
• Godfrey-Smith, Peter (2002) Gestalt-Switching and the Evolutionary Transitions
• West, Griffin and Gardner (2009) Social semantics: how useful has group selection been?
• West, S.A., Griffin, A.S. & Gardner, A. (2007) Social semantics: altruism, cooperation, mutualism, strong reciprocity and group selection.
• Gardner, A. and Grafen, A. (2008) Capturing the superorganism: a formal theory of group adaptation
• Lehmann, L (2007) Group selection and kin selection: Two concepts but one process
• Kohn, Marek (2008) Darwin 200: The needs of the many
• Traulsen, A. (2010) Mathematics of kin- and group-selection: formally equivalent?
• Leigh, E.G. Jr. (2010) The group selection controversy.
• Queller, David C. (2012) Two languages, one reality
• Queller, David C. (1992) Quantitative genetics, inclusive fitness, and group selection.
• Hamilton, W. D. (1975) Innate Social Aptitudes of Man: an Approach from Evolutionary Genetics
• David Sloane Wilson and E. O Wilson (2007) Rethinking the theoretical foundation of sociobiology.
• Grafen, Alan (2007) Natural Selection, Kin Selection and Group Selection.
• Johnson, Eric Michael (2012) The Good Fight.
• Wilson, David Sloan (2012) Clash of Paradigms: Why Proponents of Multilevel Selection Theory and Inclusive Fitness Theory Sometimes (But Not Always) Misunderstand Each Other
• Wilson, David Sloan (2012) Richard Dawkins, Edward O. Wilson, and the Consensus of the Many
• Wade, Michael J., Wilson, David Sloane, Goodnight, Charles, Taylor, Doug, Bar-Yam, Yaneer, de Aguiar, Marcus A. M., Stacey, Blake, Werfel, Justin, Hoelzer, Guy A., Brodie, Edmund D. III, Fields, Peter, Breden, Felix, Linksvayer, Timothy A., Fletcher, Jeffrey A., Richerson, Peter J., Bever, James D., Van Dyken, J. David and Zee, Peter (2009) Multilevel and kin selection in a connected world
• Bijma, P. and Aanen, D. K. (2009) Assortment, Hamilton's rule and multilevel selection.
• Breden, F. (1990) Partitioning of covariance as a method for studying kin selection.
• Wade, M. J. (1980) Kin selection: its components.
• Frank, S. A. (1994) Genetics of mutualism: the evolution of altruism between species
• Okasha, Samir (2010) Altruism researchers must cooperate

Group selection turns out to be kin selection

It was observed early on that most of the evidence that was cited as favouring group selection seemed to be explained rather well by kin selection.

Slime mold aggregation typically consisted of identical clones - the highest level of relatedness it is possible to get. The ant and termite families that group selection enthusiasts loved got a long list of nice quantitative predictions from kin selection theory. The evolution of chickens that supposedly counted as evidence for group selection was explained neatly by kin selection: the chickens were couped up with their close relatives.

It was argued that group selection was needed to explain cooperation between strangers who were not genetically related. However, this line of argument ignored cultural kin selection - much cooperation between strangers could be explained neatly in terms of shared memes - rather than shared genes.

There were other factors that explained cooperation too: including reciprocity, reputations, virtue signalling and the Allee effect. It seemed as though group selection was trying to take credit for the moves of other theories which were already well-established.

Was there anything group selection was needed for? Fortunately, this question now seems to have been answered...