Men's Y chromosome is not about to go extinct

Some evolutionary theorists have argued that the Y-chromosome (the one that determines male sex) will eventually mutate itself out of existence.

Not so, says Jennifer Hughes at the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts. She and her colleagues have just sequenced the Y chromosome of the rhesus macaque - a primate that diverged from humans around 25 million years ago. 

"Most of the Y chromosome's gene loss happened almost immediately after it stopped recombining with the X chromosome." The 19 surviving genes probably have vital biological functions, she says, and so aren't going anywhere anytime soon.