Thursday, September 01, 2005

Biologists: Male Chromosome Not In Danger Anytime Soon...

Study Says Male Chromosome Sticking Around - Yahoo! News

NEW YORK - The human Y chromosome — the DNA chunk that makes a man a man — has lost so many genes over evolutionary time that some scientists have suspected it might disappear in 10 million years. But a new study says it'll stick around.

Researchers found no sign of gene loss over the past 6 million years, suggesting the chromosome is "doing a pretty good job of maintaining itself," said researcher David Page of the Whitehead Institute for Biomedical Research in Cambridge, Mass.

That agrees with prior mathematical calculations that suggested the rate of gene loss would slow as the chromosome evolved, Page and study co-authors note in Thursday's issue of the journal Nature.

Researchers compared the human and chimpanzee versions of this region. Humans and chimps have been evolving separately for about 6 million years, so scientists reasoned that the comparisons would reveal genes that have become disabled in one species or the other during that time.

They found five such genes on the chimp chromosome but none on the human chromosome, an imbalance Page called surprising.

"It looks like there has been little if any gene loss in our own species lineage in the last 6 million years," Page said.

Advocates of Intelligent Design, however, dismissed the biologists remarks concerning the evolution of anything, and were particularly disturbed by the mention of chimps.

When asked to provide their own explanation as to the apparent deterioration of genes in the Y chromosome, they submitted the following to various newswire services:

"Thousands of years ago it was dark. An invisible man who lives in the sky wanted light and made it so. Eventually he got lonely and started making people. One day he wanted to make a girl so he took a rib from a man. This could have damaged the male parts."

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