February 22, 2012
By Neil Bowdler Science and health reporter, BBC News
Men may not become extinct after all, according to a new study.
Previous research has suggested the Y sex chromosome, which only men carry, is decaying genetically so fast that it will be extinct in five million years’ time.
A gene within the chromosome is the switch which leads to testes development and the secretion of male hormones.
But a new US study in Nature suggests the genetic decay has all but ended.
Professor Jennifer Graves of Australian National University has previously suggested the Y chromosome may become extinct in as little as five million years’ time, based on the rate at which genes are disappearing from the chromosome.
Genetics professor Brian Sykes predicted the demise of the Y chromosome, and of men, in as little as 100,000 years in his 2003 book Adam’s Curse: A Future without Men.
The predictions were based on comparisons between the human X and Y sex chromosomes. While these chromosomes were once thought to be identical far back in the early history of mammals, the Y chromosome now has about 78 genes, compared with about 800 in the X chromosome.yDr Jennifer Hughes Whitehead Institute, Cambridge, Massachusetts
Jennifer Hughes and colleagues at the Whitehead Institute in Cambridge, Massachusetts, have sought to determine whether rumours of the Y chromosome’s demise have been exaggerated.