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Inclusive fitness and the selfish gene | blogjou

Murray Gell-Mann

The Quark and the Jaguar
18 Sep 2021

Inclusive fitness and the selfish gene


A further complication in utilizing the concept of fitness arizes in higher organsisms that make use of sexual reproduction. Each such organism conveys only half its genes to a given offspring, while the remaining half derive from the other parent. The offspring are not clones, but merely close relatives. And the organism has other close relatives, the survival of which can also contribute to the propagation of genes similar to its own. Thus biologists have developed the notion of “inclusive fitness”, which takes account of the extent to which relatives of a given organism survive to reproduce, weighted according to the closeness of the relationship. (Of course inclusive fitness also takes account of the sirvival of the organism itself.) Evolution should have a general tendency to favor genotypes exhibiting high inclusive fitness, especially through inherited patterns of behavior that promote the survival of an organism and its close relatives. Tha tendency is called “kin selection”, and it fits nicely with a picture of evolution in which organisms are merely devices “used” by genes to propagate themselves. That point of view has been popularized under the name of the “selfish gene.”