Science

Men rejoice! Y-chromosome saved

Anna Raby

“The Y chromosome is dying and the big question is what happens then?” said Professor Graves, a researcher in human sex chromosomes and founder of the “rotting Y theory”, in 2009.

“You need a Y chromosome to be male… Three hundred million years ago, the Y chromosome had about 1,400 genes on it, and now it’s only got 45 left, so at this rate we’re going to run out of genes on the Y chromosome in about five million years.” I think her point here was that we are going to run out of men. Thankfully, despite Graves’ (somewhat grave) reassurances that, like certain rats and mole voles, humans would probably have found another gene to create males, we can worry no more!

Jennifer Hughes’ work with colleagues at Whitehead Institute for Biomedical Research at MIT has revealed that despite initially free-falling at a rapid rate, the Y chromosome has actually been stable for at least six million years. She declares the decline ground to a halt when humans and old world monkeys took separate evolutionary paths and that only one gene had been lost from the human Y chromosome in the 25 million years since.

“It’s clear the Y isn’t going anywhere” affirms Hughes. Yet Steve Jones, author of the book Y: The Descent of Man and professor of genetics at University College London remains confident that the Y chromosome will eventually be replaced. When asked what it would be replaced with, “ask me in a hundred million years.” was his reply.

Undecided, Darren Griffin, professor of genetics at the University of Kent in Canterbury states that a few hundred million years ago, the X and Y chromosomes were equal in size, but today, the Y chromosome holds fewer than 30 genes, whereas the X chromosome has 800 or so. He says if you actually draw a straight line on a graph, the Y chromosome’s demise will come in 4 or 5 million years. However,  David Page , another researcher at MIT, claims despite the original decline, the state of the Y chromosome now is strictly conservative and therefore all is not doomed.

So, the question still poses for many: will the Y chromosome sit happily on the edge of a cliff forever? Or will it eventually topple over? Only time will tell. Speaking of time, the key words here are “millions” and “years”; yes, let’s leave the experts to investigate it further, but, for us? There is nothing we can do except relax and enjoy the concept of (the declining state of?) masculinity.

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