SCIENTISTS fear men could be wiped out after discovering that endangered rats lack the male Y chromosome.
They say humans’ version of the gene data has been shrinking in size for years and may die out altogether.
Expert geneticists tested Ryukyu spiny rats living on a Japanese island[/caption]
Experts tested Ryukyu spiny rats living on the Japanese island of Amami Oshima.
Only a few now remain — but none has the Y chromosome.
A baby’s gender is determined by chromosomes known as X and Y, which carry our DNA.
Males have XY while females have XX.
When conceiving a child, women contribute an X while men contribute the X or Y.
Study author Professor Asato Kuroiwa, of Hokkaido University, said: “Y chromosomes in many mammals have been shrinking over tens of millions of years — and could eventually disappear.”
Award-winning geneticist Jenny Graves claimed two decades ago that our Y chromosome will eventually go.
Prof Graves, of La Trobe University, Melbourne, told New Scientist: “I think this latest piece of work is brilliant.
The evidence is very compelling.
“There is no reason to think our Y chromosome is any more robust than the spiny rat’s.”
Prof Kuroiwa said: “I agree with Jenny. I also believe the Y chromosome will disappear.”