Sunday, December 29, 2013

Book 128: The Seven Daughters of Eve

I first heard about this one from one of my mom's best friends, and thought it sounded fascinating.  I'm not sure why this then sat in my to read pile for as long as it did.  I assumed I had started reading it and lost interest but none of the first pages seemed familiar so I guess I just never got around to it.
Sykes basically explains the way that mitochondial DNA passed down from the mother can be used to trace the migration patterns of humans and how it can show how far back common ancestry goes based on mutation rates.  Once he explains everything it's a very simple concept, and it is rather fascinating.  His first use of this theory involves the Polynesian Islands which basically proves what the majority of anthropologists and others were already saying: they were settled from West to East.  There were some opposing views that argued that the islands were colonized by explorers from South America (in fact, a Norwegian made this trip on a boat to prove that theory, and I could have seen that boat at a museum in Oslo this summer if I hadn't been distracted by the other museums - if I had read this book prior to the visit, I probably would have had a greater interest).
After this success, he tries to do the same for Europe, and basically narrows European descent down to seven different women.  The part that made his theory controversial is that it showed that a good portion of European DNA is from Europe itself - before this, a predominant theory had been that the original settlers of Europe had been driven out as farmers from Mesopotamia displaced them.  Sykes's argument and proof caused quite the controversy since it went against prior common conceptions.  I guess my only question would be whether the two are truly mutually exclusive - after all, if his method only tests for maternal DNA, it ignores paternal influences.  If someone is spreading and invading, isn't it much more likely for the conquered's maternal DNA to survive since the women would more likely be raped or incorporated by the incoming men?  Turns out that later tests by a different group of scientists focusing on paternal DNA support Sykes as well, but that was kind of the one thing that came into my mind while reading this.
After explaining the science, and the debates it caused, Sykes concludes his book with seven chapters, which are kind of fake mini bios of the seven women whose DNA is found throughout Europe.  Obviously, he is just guessing as far as their personalities are concerned, but he does place them into a time and context based on what is known of civilizations at different times and locations (the number of mutations determine how far ago the last common ancestor was - all of these women had at least two daughters since they needed two of them to be considered the last common ancestor).
In the afterword, Sykes explains that further research has been done with this method, extending out to the entirety of the world, creating over 30 "daughters" of Eve or women are distinct lineages of DNA.  I definitely thought this was fascinating and it was very easy to digest and understand, even for a non-science person.

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