Wednesday, October 12, 2005

Homo testis   posted by Razib @ 10/12/2005 10:12:00 AM

This isn't big news, but confirmation of a somewhat amusing trend, Emergence of Young Human Genes after a Burst of Retroposition in Primates:

...We estimate that at least one new retrogene per million years emerged on the human lineage during the past ∼63 million years of primate evolution. Detailed analysis of a subset of the data shows that the majority of retrogenes are specifically expressed in testis, whereas their parental genes show broad expression patterns. Consistently, most retrogenes evolved functional roles in spermatogenesis...We conclude that retroduplication significantly contributed to the formation of recent human genes and that most new retrogenes were progressively recruited during primate evolution by natural and/or sexual selection to enhance male germline function.

What sort of phenotypic changes would affect fitness (differential reproduction), ergo, respond to selection? You don't have to look too high for a trait that might stick to those specifications.

Related: Sperm competition. Rate of molecular evolution of the seminal protein gene SEMG2 correlates with levels of female promiscuity.