In case anyone was either still worrying about degenerating Y chromosomes, or still feeling superior about them, depending on your sex, it seems there may not be a problem after all.
The human Y chromosome is here to stayThe male sex-determining chromosome has lost only one gene in 25 million years.
Men can breathe a sigh of relief: their sex-determining chromosomes aren't going anywhere. A study of human and rhesus monkey Y chromosomes questions the notion that the Y is steadily shedding genes and is doomed to degenerate.
In fact, the version of the Y chromosome that every human male carries around has lost just a single gene in the 25 million years since humans and rhesus macaques shared a common ancestor.
"I think it should finally put an end to the speculation about the demise of the Y. Twenty-five million years is a big chunk of the history of the Y," says Jennifer Hughes, a geneticist at the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts. She and colleague David Page led the study, which is published online today in Nature.
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To gaze even further back into the history of the Y, Hughes and her team decoded the Y chromosome of the rhesus macaque (Macaca mulatta), which has a common ancestor with humans and chimps that lived around 25 million years ago. Macaques are promiscuous, and Hughes expected to see that the macaque Y had dropped some genes and duplicated others involved in making sperm.
"It couldn't have been more different," she says. The macaque Y contained just one gene that humans have lost, and that gene resides on a particularly unstable portion of the Y. The human Y has grown much longer than the macaque's, but the genes were mostly the same.
Devious, treacherous, murderous, neanderthal, sub-human of the West.