THE notion of the "selfish gene" is the most successful scientific metaphor of the past 30 years, followed not far behind by "the extended phenotype". Both were coined by Richard Dawkins and are, as it happens, the titles of his first popular science books.
The Selfish Gene's message was that evolution is about the natural selection of genes, and genes alone. Dawkins sees them as the best candidates to be evolution's units of replication. As such, the genes that are passed on are those whose consequences serve their own interests at gene level - that is, to continue being replicated - and do not necessarily serve the interests of the organism at a larger level, or at the level of groups of organisms. It is "as if" these genes are being selfish, not that they are really selfish.
The Extended Phenotype develops this idea, arguing that in their drive for ...
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