Can gene-inactivating mutations lead to evolutionary novelty?


Andrew W Murray. 5/18/2020. “Can gene-inactivating mutations lead to evolutionary novelty?” Current Biology, 30, 10, Pp. R465. Publisher's Version


Evolutionary novelty is difficult to define. It typically involves shifts in organismal or biochemical phenotypes that can be seen as qualitative as well as quantitative changes. In laboratory-based experimental evolution of novel phenotypes and the human domestication of crops, the majority of the mutations that lead to adaptation are loss of function mutations that impair or eliminate the function of genes rather than gain of function mutations that increase or qualitatively alter the function of proteins. I speculate that easier access to loss of function mutations has led them to play a major role in the adaptive radiations that occur when populations have access to many unoccupied ecological niches. I discuss four possible objections to this claim: that genes can only survive if they confer benefits to the organisms that bear them, antagonistic pleiotropy, the importance of pre-existing genetic variation in populations, and the danger that adaptation by breaking genes will, over long times, cause organisms to run out of genes.

Last updated on 05/18/2020