By 3 News online staff
Men aren't going extinct, new research suggests, contradicting previous studies which predicted an all-female future.
The Y chromosome, which makes men what they are, has decayed over the ages to the point where it has only 19 of its original 800 or so genes, leading scientists to suspect one day it would vanish.
In contrast, the X chromosome still has its full set.
Women have two X chromosomes, and men have one X and one Y. When a new person is conceived, DNA from the mother and father swap genes, but the Y chromosome shares very little of its information with X, to stop females getting male genes.
Because of this, most of the Y chromosome's genes are passed along without change and innovation, and eventually lose their usefulness and disappear.
But Jennifer Hughes and David Page at the Whitehead Institute in Cambridge, Massachusetts, say in the last six million years the Y chromosome has not lost any genes, and in the last 25 million years, it has only lost one, suggesting its decay could be over.
Humans have common ancestors with rhesus monkeys and chimpanzees, and by sequencing their DNA, the researchers were able to see how much change the Y chromosome had gone through since their lineages diverged.
"The Y is not going anywhere and gene loss has probably come to a halt," Hughes told BBC News.
"We can't rule out the possibility it could happen another time, but the genes which are left on the Y are here to stay."
The researchers can't say what the genes that remain actually do, but that they must be important.
Eight of the genes have managed to get onto the X chromosome, but that's not enough for it to go it alone – so the Y chromosome, and therefore men, is sticking around.
3 News