Adam's Curse: A Future Without Men

  • Bryan Sykes
Bantam Press: 2003. 300 pp. £18.99

I think 2003 must have been the Year of the Sex Chromosomes. On the heels of Steve Jones' Y and David Bainbridge's The X in Sex (both reviewed in Nature 423, 223; 2003) comes Adam's Curse: A Future Without Men (note the absence of a question mark).

After reading Bryan Sykes' delightful article on the history of the Sykes Y chromosome (Am. J. Hum. Genet. 66, 1417–1419; 2000) and his successful book The Seven Daughters of Eve (Norton, 2001), I looked forward to this book. I admire authors who can interest non-scientists in genetics — a vital skill if we are to cultivate an informed public to debate the manipulation of sex and reproduction.

Indeed, the book is fun to read — the writing style is lively, the images fresh and witty, the explanations of basic genetic principles apt and accurate, even inspired. Like Y, Adam's Curse centres on sexual conflict, here the war between the mother's mitochondrial genome and the father's Y chromosome. Sykes traces the spread of the Y chromosome in space and time, enriching the account with the history of Vikings, Polynesians and Genghis Khan.

The author's focus on his own family is a good device to explain how the Y chromosome gets around and to introduce the history of families and surnames, migrations and conquests. But the focus on Sykes and his family, Sykes' blood cells and the Sykes Y chromosome, then Sykes' ideas and finally Sykes' wild speculations, rather gives the impression that the entire field was explored single-handedly by Bryan Sykes, genetic supersleuth.

Of particular interest to me were the dire predictions of the imminent decay of the Y chromosome. Sykes calculates from the frequency of Y mutations in men (can it really be high as 2%?) that the fertility of the whole human population will plummet within 125,000 years (upping the ante on my calculation of 9 million years). But does the disappearance of the Y chromosome, as Sykes avers, really mean the extinction of humankind unless we can dispense with the imprinting of at least 100 genes and embrace parthenogenesis? I don't see why. After all, several spermatogenesis genes, and even SRY, have already been dumped in other species with no ill effect.

Indeed, the book abounds with bold assertions hedged by “I can't prove it but...”. Families that produce more boys than girls (the Sykes clan again, documented by dusty records from a village school) expose a superselfish Y chromosome. Newspaper accounts of female-only families are proof of toxic, Y-hating, superselfish mitochondria. Even the 'gay gene' turns out to be a mitochondrial plot.

I welcome speculation in popular-science books. Sharing with the public the leaps of imagination that make science exciting and creative might banish its image as gadget-driven and boffin-dominated. But speculation on speculation becomes tedious, and ultimately I feel that the central argument degenerates under its weight — like the Y chromosome itself.