The Seven Daughters of Eve: The Science That Reveals Our Genetic Ancestry
by Bryan Sykes
W W Norton and Company (2002)
This book is an account of geneticist Bryan Sykes’s discovery of the value of mitochondrial DNA in tracing the maternal lineage of all contemporary human beings to a few dozen cave women. Mitochondrial DNA is unique in that it’s only inherited from the egg (sperm discard their mitochondria once they penetrate the egg). It’s also far less genetically complex than nuclear DNA and only rarely undergoes mutation.
Sykes first used his discovery to establish that Polynesian navigators (including New Zealand Maori) originated from Taiwan or coastal China, and not south America, as claimed by Thor Heyerdahl. Heyerdahl came to public attention after piloting the balsa raft Kon-Tiki from the South American cost to the Tuamotu islands near Tahiti.
Sykes also used mitochondrial DNA to settle a longstanding debate over the origin of Europe’s agricultural revolution. The old view was that Europe’s hunter gatherers had been overwhelmed and displaced by an “invasion” of Middle Eastern farmers. Sykes’s genetic studies revealed otherwise – only about 17% of current Europeans carry typical Middle Eastern mitochondrial DNA. This suggests that Europe’s hunter gatherers gradually learned techniques for domesticating plants and animals from a small number of Middle Eastern farmers.
I had real problems with the final section of the book, in which Sykes fantasizes about each of the seven “daughters of Eve” (aka clan mothers) who are direct ancestors of nearly all people of European ancestry. His reconstructions depart significantly from existing anthropological studies of hunter gatherer societies – especially his portrayal of males heading households of nuclear families, his minimization of women’s roles in domesticating plants and most farm animals, and his heavy emphasis on hunting as the primary source of nutrition among hunter gatherers.
His premise that hunter gatherer females nursed 3-4 year old children every four hours (resulting in natural birth control) is just plain wrong. Although hunter gatherer females typically breast fed children for fours years or more, after age 12-18 months breast milk became a secondary source of found as young children shared shared the same solid food their parents ate.