Gene Genesis: Scientists Observe New Genes Evolving from Mutated Copies
The history of life on Earth has been marked by the evolution of new genes—humans clearly have more genes with more diverse functions than do amoebas. So where do these additional genes, with their new roles, come from? Analysis of genomes shows that the duplication and modification of existing genes seems to be a major avenue for such innovation.
Conventional wisdom had it that duplicate genes provide raw material for evolution. The original gene continues to do its job, whereas the other copy is free to evolve in a different direction. But this model requires that natural selection should spare the extra gene copies until they had a chance to change for the better. This problem bothered microbiologist Dan Andersson and geneticist John Roth. To better explain how new genes could evolve, they suggested a modification of the old model: instead of waiting around for a beneficial mutation, perhaps the beneficial mutation comes first.