Does inclusive fitness theory miss part of the picture?

...Huh. That page is by Eliezer Yudkowsky, and apparently it was written back in June 2009. It seems that writing something up on the wiki is a very poor way to get it discussed.

The argument given seems to make sense, but with two noteworthy caveats. The first is that, while group selection doesn't work, kin selection does, and in an organism that mostly interacts with close relatives, altruism only towards relatives may not be meaningfully distinct from altruism towards all others of its species. The second issue is that group selection can interact with the founder effect, which is where a very small group enters a new environment and founds a colony that turns into a large population. In that case, altruistic genes in the original founders affect the probability that the colony succeeds; so if an environment is particularly hard to colonize, and many attempts are made, it may be that only a group with some altruistic genes could succeed.

Interestingly, group selection has been observed in microorganisms:

Experiments with actual groups illustrate the point. Pseudomonas fluorescens bacteria quickly suck all the dissolved oxygen out of a liquid habitat, leaving a thin habitable layer near the surface. But some bacteria spontaneously develop a beneficial mutation. These group-saving individuals secrete a polymer that enables bunches of individuals to form floating mats. As a mat, all the bacteria survive, even though most of them expend no metabolic energy producing the polymer. But if the freeloaders get greedy and reproduce too many of their kind, the mat sinks and everybody dies, altruists and freeloaders alike. Among these bacteria, then, groups that maintain enough altruists to float outcompete groups with fewer altruists than that minimum number. The former groups survive, grow and split up into daughter groups. Thus, altruistic individuals can prosper, despite the disadvantage of expending precious resources to produce the polymer.

There are four letters in a later issue of Nature commenting on Nowak et al. (All of this is behind paywalls, sorry.) All of the contributors seem to agree (whether wholeheartedly admitting it or not) that inclusive fitness theory is, in effect, a theorem derivable from basic individual selection theory, not a separate principle. Nowak et al. further argue (mathematically) that the preconditions for inclusive fitness theory are rarely satisfied in practice, and that direct arguments from individual selection are a better tool for understanding the relevant phenomena.

Demathematised, one of the points Nowak et al. make is that individual fitness theory takes account only of the benefit an organism's costly actions provides to its relatives, but not of any reciprocal benefits. It therefore underestimates the amount of cooperation one might expect to see.

Eliezer's original article on group selection said some things that I think ought to be included in the wiki article: While the preconditions for group selection appear unlikely to hold in the wild (a similarity with inclusive fitness theory), they can be produced in the laboratory. The result of imposing selection for limited colony size of certain insects was not that the insects limited their own numbers, but that they limited each others' within their colony, by eating their eggs and larvae.

Novak co-authored a paper called "Transforming the dilemma". I'd say it's relevant:

Whenever evolution ‘constructs’ a new level of organization, cooperation is involved. The very origin of life, the emergence of the first cell, the rise of multi-cellular organisms, and the advent of human language are all based on cooperation. A higher level of organization emerges, whenever the competing units on the lower level begin to cooperate. Therefore, we propose that cooperation is a third fundamental principle of evolutionary dynamics besides mutation and selection. Evolution occurs in populations of reproducing individuals. Inaccurate reproduction can lead to mutation. Mutation can lead to selection. Selection can lead to cooperation.

The analysis that follows actually uses game theory:

In the Prisoner’s Dilemma, defectors dominate cooperators unless a mechanism for the evolution of cooperation is at work. We will discuss five mechanisms for the evolution of cooperation: direct reciprocity, indirect reciprocity, kin selection, group selection, and network reciprocity (or graph selection).

ETA: I hope it's alright that I use the comments section as a workspace; I'm trying to dig through the literature to see what the fuss is all about.

It seems like this is more introductory than the paper I posted about above. It features an interesting theoretical argument:

Consider a population that is subdivided into groups. The fitness of individuals is determined by the payoff from an evolutionary game. Interactions occur between members of the same group. We model stochastic evolutionary dynamics. In any one time step, a single individual from the entire population is chosen for reproduction with a probability proportional to its fitness. The offspring is added to the same group. If the group reaches a critical size, n, it will divide into two groups with probability q. The members of the group are randomly distributed over the two daughter groups, see Fig. 1. With probability 1− q, the group does not divide, but a random individual of the group is eliminated. Therefore, n resembles the maximum number of individuals in a single group. The total number of groups is constant and given by m; whenever a group divides, another group is eliminated. These assumptions ensure that the total population size is constrained between a lower bound, m, and an upper bound, mn.

Our simple model has some interesting features. The entire evolutionary dynamics are driven by individual fitness. Only individuals are assigned payoff values. Only individuals reproduce. Groups can stay together or split (divide) when reaching a certain size. Groups that contain fitter individuals reach the critical size faster and, therefore, split more often. This concept leads to selection among groups, although only individuals reproduce. The higher-level selection emerges from lower-level reproduction. Remarkably, the two levels of selection can oppose each other.

This presentation is a good source for the inclusive fitness side of the debate. It's by Stuart West, evolutionary biologist at Oxford.

In the talk, West, a proponent of inclusive fitness, says:

[There's] also the general point of [...] Occams Razor: If we can explain everything more generally without it, what use is it?

This debate is making me boggle. Both sides seem to claim that their theory is more general than the other, and that therefore by Occams Razor we should eliminate the other theory.