Y-chromosomes (that's us, men) evolve faster than X-chromosomes.
The Y chromosome, found only in males, has evolved faster than expected in humans and chimpanzees over the past 6 million years since the two species emerged from a common ancestor, researchers report.
The new study challenges the widely held belief that the mammalian Y chromosome is slowly decaying or stagnating.
The Y chromosome is present in males (who have one Y and one X chromosome) but not in females (who have two X chromosomes).
"The region of the Y that is evolving the fastest is the part that plays a role in sperm production. The rest of the Y is evolving more like the rest of the genome, only a little bit faster," study first author Jennifer Hughes, of the Whitehead Institute for Biomedical Research in Cambridge, Mass., said in a news release from the Massachusetts Institute of Technology. Hughes is a postdoctoral researcher in the lab of Whitehead director David Page. [More]
Oh yeah - we're about change.