Selfish Gene Theory Of Evolution Called Fatally Flawed

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Yaneer Bar-Yam, Formalizing the gene centered view of evolution, Advances in Complex Systems 2: 277-281 (1999).

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Also available at Los Alamos arXiv

(Editor's Note: This story is based on a brief release submitted by David R. Efros of the New England Complex Systems Institute.)

The "selfish gene" theory proposed by Richard Dawkins has been an influential thread in scientific and popular thinking for the past 25 years. The key concept is that any action is a supremely self- serving one on the part of the actor, devoid of motivation to serve the larger group to which the actor belongs (i.e., genes as parts of an organism).

As far as Dawkins is concerned, the struggle for survival always takes place at the scale of the individual gene. Instead of thinking that organisms compete, Dawkins would have us think that different versions of the gene, known as alleles, compete.

(The reason we shouldn't think about organisms as competing is that we would then have to think about genes that are part of the same organism as cooperating -- which, according to Dawkins, genes don't really do.)

The "selfish gene" perspective has not gone unchallenged. Among others, the well-known evolutionary biologist Richard Lewontin and philosopher Elliott Sober have raised specific objections to this focus on the gene.

The debate remains unresolved because the gene-centered view is, demonstrably, partially valid.

Having difficulty figuring out when it works and when it doesn't, some scientists carried the argument over into the political/ philosophical realm:

Arguments about the gene-centered view often focused on whether people should believe that altruism exists at all.

In the current issue of Advances in Complex Systems (February-April), Dr. Yaneer Bar-Yam, president of the New England Complex Systems Institute and an expert on the application of mathematical analysis to complex systems, contends that the selfish-gene theory of evolution is fatally flawed.

If his mathematical proof gains general acceptance, it will shut the door on controversial "gene-centered" views of evolution.

Bar-Yam, in the upcoming article, proves that the "selfish gene" approach is not valid in the general case. He demonstrates that the gene-centered view, expressed in mathematical form, is only an approximation of the dynamics actually at work.

And this approximation does not always work. Specifically, it breaks down when a process called symmetry breaking enters the picture. Symmetry breaking is a concept borrowed from physics. It corresponds, in evolution, to trait divergence of subpopulations.

In this view, genes relate to each other differently than theory would predict when the organisms to which they belong are themselves components of groups that are at least partially distinct, one from another.

The key to Bar-Yam's analysis lies in recognizing three levels of structure in nature: the gene, the organism and the group (or network) of organisms.

According to Dr. Bar-Yam, the effective evolutionary fitness of each allele depends on the distribution of alleles in the population. Thus, the fitness of an allele is coupled to the evolution of other alleles.

The self-selecting process predicted by the selfish-gene model becomes quickly skewed when correlations in reproduction exist which give rise to less than complete mixing of alleles in the gene pool. This may occur through several mechanisms, including mate selection and partial geographic isolation.

The gene-centered view, Dr. Bar-Yam points out, can be applied directly only to populations in which sexual reproduction causes complete allelic mixing. (Such populations are called "panmictic" in biology.)

Many organisms are part of populations that do not satisfy this condition. Thus, the gene-centered view and the concept of the "selfish gene" does not describe the dynamics of evolution, Dr. Bar-Yam concludes.