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Biologists have predicted that the Y chromosome, the DNA which makes men, men, was gradually dying out and that it would lead to the extinction of the male species. A team of researchers just proved that this isn't going to happen.

Th X and Y chromosomes were the same size and shape and about 166 million years ago, a huge chunk of the Y chromosome was turned upside down and reinserted. No one knows why this happened, but the Y chromosome lost 781 of the 800 genes it originally shared with the X chromosome.

According to research from the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts, the team of researchers compared the human Y chromosome to that of the rhesus macaque, a primate that diverged from humans 25 million years ago.

The monkey's Y chromosome contains 20 genes, and 19 of them are identical to those of the human's Y. The research appears in this week's issue of Nature, and Jennifer Hughes says:
"We finally have empirical data that the Y chromosome has held steady over the last 25 million years. Most of the Y chromosome's gene loss happened almost immediately after it stopped recombining with the X chromosome."
[Nature and New Scientist via Gawker; Image: The National Institute of Standards and Technology]