January 10, 2014, 10:39 AM
It’s science Friday, and the big news is that the male sex is not about to be phased out.
While that may be bad news to a select few out there, the majority of us will be relieved. In a paper entitled, “Natural selection reduced diversity on human Y chromosomes,” researchers over at the University of Wisconsin-Madison delved into the notion that maybe no one really needs the Y chromosome.
For those of you (including this reporter) who need a refresher on why the Y is so important: Each person has one pair of sex chromosomes in each cell. Males have one X and one Y chromosome, and females have two X’s. Last month, some researchers reported they had shuffled around genes in mice to create Y-less males that could produce normal offspring, leading some commentators to wonder whether the chromosome is superfluous.
“The Y chromosome has lost 90% of the genes it once shared with the X chromosome, and some scientists speculated that the Y chromosome will disappear in less than 5 million years,” said Wilson Sayres, evolutionary biologist and a lead author on the paper. “Our study demonstrates that the genes that have been maintained, and those that migrated from the X to the Y are important, and the human Y is going to stick around for a long while.”
And the paper says the Y chromosome is so small — with just 27 unique genes where others have thousands — it means it’s lean and mean, or rather, stripped down to just what’s required. The Y has been on the decline for the past 200 million years.
“Melissa’s results are quite stunning,” Nielson told Science Daily. “They show that because there is so much natural selection working on the Y chromosome, there has to be a lot more function on the chromosome than people previously thought.”
– Barbara Kollmeyer covers markets and delves into The Margin at times for MarketWatch.