Will men go extinct? New research says it's unlikely.
A recent study from the Whitehead Institute indicates that the male Y chromosome is unlikely to disappear, as was previously thought.
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A comparison of the rhesus Y chromosome with that of modern men revealed that reports of the chromosome's decay have been exaggerated. The two sex chromosomes are remarkably similar, Hughes told LiveScience. [5 Myths About the Male Body]Skip to next paragraph
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"For the most part, the gene content has not changed for 25 million years," she said.
The small amount of gene loss in that timeframe all occurred in the youngest 3 percent of the Y chromosome — the section that most recently stopped mixing and matching with the X chromosome. The findings suggest that while gene loss is rapid at first, it levels off into almost nothing.
"The rate of decay appears to have just basically ceased at this point," Hughes said.
The future of men
The reason for the Y's stability likely comes down to the fact that it simply can't lose anymore genes without vanishing completely. In other words, the genes that remain on the Y chromosome are so crucial that losing them might ensure that the organism doesn't survive. Natural selection favors those who can survive to pass on their genes, so overly degraded Ys simply end up on the trash heap of evolution.
Hughes and her colleagues plan to sequence the genomes of even more distantly related mammals, including mice, rats, marmosets and opossums, in hopes of tracing the evolution of the male chromosome back even further. But for now, the future of men seems solid.
"This is clear evidence that the Y is not going anywhere," Hughes said.
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