Weak genes could spell end of men

Pictured is a normal karotype of the x and y chromosomes. Changes to the Y chromosome found in men could mean it will disappear.

Pictured is a normal karotype of the x and y chromosomes. Changes to the Y chromosome found in men could mean it will disappear.

Published Apr 3, 2013

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London - Men are living on borrowed time, according to a leading female scientist.

Professor Jenny Graves even claims the male of the species is heading for extinction.

This is because changes to the Y chromosome found in men could mean it will disappear. But other experts say there is no need to panic as the process, if it happens, will take millions of years.

Professor Graves, one of Australia’s most influential scientists says that the male sex-determining chromosome is much more fragile than its female counterpart, the X chromosome.

Women have two X chromosomes, which help each other, whereas men have an X and a Y.

Professor Graves’s prediction hinges around the number of genes on each. The female X chromosome contains about 1 000 genes. The Y started with the same number but over hundreds of millions of years it has fallen away to fewer than 100.

Professor Graves, of Canberra University, told the Australian Academy of Science: “The X chromosome is all alone in the male but in the female it has a friend, so it can swap bits and repair itself. If the Y gets hit, it’s a downward spiral.”

The genes that remain on the Y chromosome are mostly “junk” she said, other than the SRY, which determines an embryo’s sex. This means the process that ensures enough males are born may eventually be threatened.

“It’s a lovely example of what I call dumb design,” Professor Graves said. She estimates it will take five million years for the Y chromosome, and men, to vanish.

But Professor Robin Lovell-Badge, a sex chromosome expert from the National Institute for Medical Research in London, said studies show the decay occurs in bursts and the Y chromosome has not lost any genes for at least 25 million years.

Professor Chris Mason, of University College London, said that, in any case, medicine will have plenty of time to catch up.

Professor Graves says that when the Y chromosome goes, another could take on the role –leading to a new human species. - Daily Mail

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