The book has a wealth of interesting information as well as theories. Bohannon has an appealing, informal, occasionally even sassy style. At the same time, she is a scientist, and is quick to use qualifiers to distinguish fact from theory. Facts may be based on journal articles, and as she recognizes, some of these are subject to future challenge. In developing theories, Bohannon looks to human physiology, anthropology, evolution, the animal world - and logic.
I underline passages in my Kindle, and in reviewing my notes, I did see certain subjects appear in widely separated pages, and occasionally the material is inconsistent, which does make me question the book’s organization to some extent. For readers who especially enjoyed the way Bohannon brings to life some of our very distant ancestors, they might like to read “The Last Days of the Dinosaurs” by Riley Black.
Why menopause? Bohannon’s answer is that a female does not develop new egg follicles after birth, and loses some each year; yet she now often lives longer than the follicles last. Chimpanzees in captivity, with extended life, can outlive their follicles. Animals, like some whales, can reach menopause. Is there an evolutionary advantage to this? Menopausal whales do not spend more time taking care of grandchildren, etc. In the face of the volatile climate in which hominins evolved, relatively quick changes in average yearly temperatures/precipitation, a long memory provided by the menopausal may prove very useful indeed to a group’s survival.
Bohannon cites physiological facts for why females tend to live longer, once they survive childbirth at least, and this is true of other species. “The male cardiovascular system is more prone to higher blood pressure from an early age.” “Male brains seem to suffer more extensive inflammation and lesions around injury sites than females’ do”- “and this might be because progesterone and the estrogens—the classic female sex hormones—have a protective effect on brain tissue, dampening that inflammatory response. “
Childbirth was very dangerous even for our Habilis hominin ancestors, even more because of the wider shoulders than the bigger head of the newborn. Learning about plants with pharmaceutical benefits helped, but help from other women in giving birth was important in aiding group longer term survival. The long time babies were so dependent may have helped lead to monogamy to enlist father’s help, but once male parenthood was (relatively) certain, it was possible for prestige to be inherited thru males, and coalition of males might form to protect their status.
Surprising to me, Bohannon notes that Islam at its inception treated women more as equals. “The slow decline of that civilization also happened to start when Islam absorbed Byzantium and became more influenced by Western thought, including the increased seclusion of women and girls, so popular in Persia, and the de-emphasis of the importance of education and worldliness”.
SummerMaple