Well-known Oxford geneticist Sykes (The Seven Daughters of Eve
), in this lively and thought-provoking book, gives a genetic twist to the battle between the sexes. All human existence, he says, stems from the battle between the X and Y chromosomes to further their own reproduction at the expense of the other. The Y chromosome is passed on only by fathers, while mitochondrial DNA is passed on only by mothers. Sykes shows that many members of several Scottish clans (most notably the Macdonalds) can be traced via their Y chromosomes back to a common ancestor. Researchers have also been able to trace the extent of Viking settlement and intermarriage in the British Isles and northern Europe through Y chromosome distribution. Sykes's argument for a genetic role in homosexuality will undoubtedly be controversial. Using Dean Hamer's pedigrees, he claims that evidence points less to a "gay gene" than to mitochondrial DNA playing the leading role in a Machiavellian plot to further its own reproduction. Sykes concludes by noting that, as evidenced by declining sperm counts and high percentages of abnormal sperm, among other variables, the Y chromosome is a genetic mess and is deteriorating so quickly that men could become extinct. Those who find that a happy thought will want to snap up this book, as well as readers interested in learning what our chromosomes tell us about where we came from and where we may be headed. 6 illus. (Apr.)
