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[escepticos] Selfish Gene Theory Of Evolution Called Fatally Flawed
> Selfish Gene Theory Of Evolution Called Fatally Flawed
> 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
> 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
> 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.
> (Editor's Note: This story is based on a brief release submitted by David
> R. Efros of the New England Complex Systems Institute.)
> [Contact: Dr. Yaneer Bar-Yam]