Adam's Curse: A Future without Men

Rating:
Summary: Hard science mixed with bizarre speculation
Review: The book's main idea is that the Y-chromosome, passed on only from father to son in mammals, is locked in a Darwinian battle to the death with the m-DNA passed on only from mothers. As a consequence, Sykes opines that the human race (or at least its male half) will go extinct in around 150 millenia unless it saves itself through genetic engineering.

Most of the book lays down the groundwork for this idea, and this is a fascinating introduction to modern genetics.The idea itself however, is still speculative, with little or no evidence to back it up.

It is not clear that the battle between m-DNA and the Y-chromosome is a zero-sum game from the point of view of an INDIVIDUAL gene (m-DNA and the Y-chromosome are clusters of several genes).

For example, Sykes suggests that m-DNA may sabotage the performance of sperm since it is indifferent to their success or failure. An individual m-DNA gene in sperm however is very likely to have an identical copy of itself in the target egg, so that it is to its expected benefit to help the sperm rather than hinder it.

In the example that Sykes gives in Chapter 22 based on a Spanish experiment, "Tara" m-DNA seems to act to sabotage its sperm by slowing them down, consistent with Sykes' theory of an evolutionary struggle between m-DNA and males, but "Helena" m-DNA does the opposite. As Sykes himself points out however, "Helena" m-DNA is by far the most successful.

A even better strategy for sperm m-DNA would be to tailor the sperm performance to the m-DNA in the mate's egg if possible. If the genetic distance between the sperm m-DNA and the egg m-DNA is lower, the sperm performs better and vice versa.

It is interesting that many societies traditionally arranged marriages between maternal cousins. From the point of view of m-DNA, a man and his mother's sister's daughter (or even his maternal grandmother's sister's daughter's daughter) are identical twins, with 100% of their m-DNA in common, and in such an arrangement, his children will inherit his m-DNA as assuredly as if he had passed it on himself. An m-DNA gene that helps sperm will spread much faster in such a society than one that cripples them.

An even more interesting strategy for a sperm m-DNA gene would be to give X-bearing sperm an advantage if the target egg's m-DNA contained the gene, and to give Y-bearing sperm an advantage if the egg m-DNA did not. In the latter case, this would be a way of sabotaging the competing m-DNA gene in the egg. An m-DNA gene that encourages this behavior would eventually wipe out a competing gene that simply sabotages all its male carriers.

If something like this happens, we would be likely to see more boys born in families where the parents are genetically more separated, say in inter-racial couples. Perhaps this may be the reason why males often lust after foreign females (the motivation behind many wars). As Sykes suggests, this may be the Y-chromosome's way of making more Y-chromosomes. But far from competing with a man's m-DNA genes, his Y-chromosome genes may be in a strategic partnership with them!

Rating:
Summary: Adam's Curse
Review: This was an excellent follow-up to "The Seven Daughters of Eve". It provides insight into the origin of human life based on genetic testing and historical events. It is a great balance of scientific data and recorded history, with all the intrigue of a mystery novel. The author maintains his factual focus throughout the book with the exception of Chapter 21, in which he momentarily mutates into a flaming liberal, explaining how "The blind rage of the male..... deliberately enslaved the female". In all other chapters he maintains a scientific focus on "natural selection", concluding with a carefully calculated prediction about the demise of the Y chromosome.

Rating:
Summary: Adam's Curse
Review: This was an excellent follow-up to "The Seven Daughters of Eve". It provides insight into the origin of human life based on genetic testing and historical events. It is a great balance of scientific data and recorded history, with all the intrigue of a mystery novel. The author maintains his factual focus throughout the book with the exception of Chapter 21, in which he momentarily mutates into a flaming liberal, explaining how "The blind rage of the male..... deliberately enslaved the female". In all other chapters he maintains a scientific focus on "natural selection", concluding with a carefully calculated prediction about the demise of the Y chromosome.

Rating:
Summary: A Somerled Descendant Speaks
Review: Unlike the other Amazon reviewers of the book, I am not an outside observer ... I'm actually in the book, as I'm one of the "Somerled people" he has a whole chapter about. That is, I share the same DNA as the MacDonalds he tested and claimed were descended from Somerled, a Viking who was the hero of the Gaelic northern Scots.

This is a wonderful chapter, well written and compelling ... especially for me! It's also quite correct. Unfortunately Prof. Sykes won't share his DNA results with other researchers, genealogists, and the general Clan Donald membership, so a new study was set up by the Clan Donald, and I am privy to their actual numbers. They are rock solid proof.

Seeing the actual numbers .... the Clan Donald study has published the most likely actual DNA marker numbers for Somerled ... leads farther back. Sykes's next chapter after MacDonald is about Genghis Khan, who hailed from central Asia. Interestingly, and this is where secrecy can be counterproductive, someone noticed that Somerled numbers, as well as lots of Icelanders' ones, showed a close affinity for men in a certain central Asian tribe. Time will tell whether the Vikings themselves came from central Asia. Stay tuned.

I found most of the book, not just my own chapter, quite entertaining, except for the part that makes up the title. It is simply baloney. As others have reviewed, Sykes has a good popular style and gets across a goodly dose of the science of DNA to the non-genealogist layman. It's just the disastrously stupid idea that human men will disappear ... it's odd he does not note that the exact same argument applies to all mammals .... and they've been around a LONG time ... that ruins this book. I need not say much more, as others have pilloried Sykes sufficiently for his transgressions.