New Clues to Sex Anomalies in How Y Chromosomes Are Copied
By NICHOLAS WADE
Published: September 14, 2009
http://www.nytimes.com/2009/09/15/science/15chrom.html?_r=1 (http://www.nytimes.com/2009/09/15/science/15chrom.html?_r=1)
The first words ever spoken, so fable holds, were a palindrome and an introduction: "Madam, I'm Adam."
A few years ago palindromes — phrases that read the same backward as forward — turned out to be an essential protective feature of Adam's Y, the male-determining chromosome that all living men have inherited from a single individual who lived some 60,000 years ago. Each man carries a Y from his father and an X chromosome from his mother. Women have two X chromosomes, one from each parent.