Prospective kin

Organisms treat their mates better than average conspecifics - even before they have had any offspring with them.

It isn't hard to think of reasons for this, but many of of those reasons invoke the idea of prospective kin - unborn children.

Most children have a probability of becoming an ancestor - and it is possible to extend this idea to children that haven't been born - and to children that haven't been even conceived.

Pretty standard kin selection models can thus be applied to courtship behaviour, bower construction, nuptual gifts - and so forth. These are cases where cooperative behaviour without relatedness occurs. In fact, there is relatedness - relatedness to unborn children.

Disagree with Steve Frank

I read Steve Frank's paper A new theory of cooperation recently. Steve Frank is an expert, but I thought that this paper was mostly wrong. The theme of the paper is that suppression of competition within groups represents a new theory of cooperation - that beyond kin selection and reciprocity. He credits the development of the idea to Richard Alexander - in The Biology of Moral Systems.

Many of the examples of suppression of competition within groups Steve gives are due to kin selection. Steve disagrees with this, writing:

[...] the main weakness of the theory was also apparent. Extensive cooperation occurs between nonrelatives. Different genes in genomes are functionally integrated but not related. Larger human societies often have many highly cooperative but distantly related individuals. Some of this cooperation between nonkin can be explained by extensions of reciprocity to a general notion of mutual benefit for interacting partners (West Eberhard 1975).

In the early 1980s, kin selection plus these extended notions of reciprocity were the main conceptual tools. Those limited conceptual tools led to blind spots about unsolved problems. Only rather forced theories of mutualism could work for the nearly complete integration of genes into cooperative genomes. Only a very enthusiastic belief in the scope of reciprocity could explain the broad social integration in larger groups of weakly related human

However, cooperation between groups of "unrelated humans" that is not due to reciprocity has turned out to be largely associated with cultural kin selection. This is kin selection applied to memes - not genes. Many of Steve Frank's examples fit onto the familiar kin selection / group selection axis - though he apparently doesn't fully realise this.

There is indeed another force that produces cooperation besides reciprocity and kin selection - and that is "manipulation". Manipulation is where agents impose their wills on other agents. Teams sometimes cooperate because they are cooerced into doing so by supervisor figures. Manipulation helps to explain suppression of competition in cooperative genomes. The efforts of individual genes to bypass meiosis is thwarted by the "parliament of genes" in the genome. Manipulation isn't the same as kin selection or reciprocity - so Steve Frank's paper is partly correct.

However, I think that there's a good reason to call this "manipulation" and not "suppression of competition". "Suppression of competition" is just another way of saying "cooperation". Explaining cooperation in terms of "suppression of competition" seems pretty circular to me.

Manipulation is responsible for the symbiont hypothesis of eusociality. This was proposed in 1934. The "parliament of genes" phrase comes from Leigh (1971). Since manipulation is such an obvious and well-known phenomenon, there may well be earlier examples of it being involved to explain cooperative behaviour. As a theory of cooperation, the idea is not exactly new - and I'm pretty sure that Richard Alexander wasn't responsible for it.

In The Biology of Moral Systems, Richard Alexander wrote:

It is a common error to suppose that something additional to nepotism and reciprocity is required to account for the structure of society. (p.153)

Here it sounds as though he repudiates this particular revolution.

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.

Kin selection, population bottlenecks, founder effect

Kin selection theory raises the possibility that organisms may use variation between them as clues to relatedness - and direct cooperative behaviour preferentially towards perceived relatives. This effect is sometimes referred to as "kin recognition".

However, this method of identifying relatives depends on the existence of population-scale variation. Population bottlenecks can destroy such variation - and may promote cooperation.

Similarly, the founder effect might also produce local regions with little variation.

These effects have been demonstrated experimentally:

• Population Bottlenecks Promote Cooperation in Bacterial Biofilms
• Kümmerli R., Gardner A., West S. & Griffin A. S. Limited dispersal, budding dispersal, and cooperation: an experimental study. Evolution 63, 939–949 (2009).

In theory, kin selection should mostly produce adaptations that work on relatedness cues that dynamically take overall population similarity into account. However, kin selection effects must work by manipulating development. Cruder measures of detecting similarity and relatedness will often be employed in practice.

Humans are among those species that have experienced a relatively recent population bottleneck - in the form of the Toba catastrophe. It is intriguing to consider the scale of the resulting increased levels of cooperation between humans that might be the result of this.

Kin selection and mimicry

Mimicry is not normally regarded as being a form of kin selection. However, it is pretty clear that mimics engage in copying of traits - and if the individual which is being copied changes its traits, the mimic tracks the changes. Thus, mimicry can be classified as a form of copying (or inheritance) that crosses species boundaries.

There are concrete examples in nature of cooperation based on mimicry. The classic example is the cuckoo. Cuckoos mimic the eggs of their hosts - often in considerable detail - in order to elicit cooperative feeding behaviour from them. The mimicry is necessary - since the hosts employ kin recognition based on egg shell traits in order to identify their own offspring. Modifications in the host eggs are eventually copied by the cuckoo lineage - proving that genuine copying is going on.

Kin selection is clearly involved in the mimicry of the cuckoo - but most would characterize it as a case of kin selection gone wrong - since the benefits go to non-kin.

An alternative analysis looks at relatedness between the copied egg shell traits. These have managed to extend themselves beyond the host species, by copying themselves into another species - thereby gaining access to the resources of a different niche. Since many host eggs perish for each cuckoo egg, this might not seem like a good deal for the trait - but such spreading between species often turns out to be a smart move in the long run.

Of course, mimicry also happens in human culture. For example, viral videos spawn parodies which are a form of cultural mimicry. There's also mimicry between culture and organic organisms - for example, Kermit the frog mimics an organic frog.

Mimicry shows that kin selection can still apply between what seem to be non-relatives, provided they share an inherited trait. Cooperation can result because the traits themselves are kin - in the sense that one of them is copied from the other one.