Massimo Pigliucci

We attempt to improve the understanding of the notion of agene being `for a phenotypic trait or traits. Considering theimplicit functional ascription of one thing being `for another,we submit a more restrictive version of `gene for talk.Accordingly, genes are only to be thought of as being forphenotypic traits when good evidence is available that thepresence or prevalence of the gene in a population is the resultof natural selection on that particular trait, and that theassociation between that trait and the gene in question isdemonstrably causal. It is therefore necessary to gatherstatistical, biochemical, historical, as well as ecologicalinformation before properly claiming that a gene is for aphenotypic trait. Instead of hampering practical use of the `genefor talk, our approach aims at stimulating much needed researchinto the functional ecology and comparative evolutionary biologyof gene action.