Survival of the Sickest
by Dr Sharon Moalem
Harper, HK$112
Why do we urinate more when it's cold than when it's warm? Why do Asians turn scarlet when they consume alcohol? In Survival of the Sickest, Dr Sharon Moalem tracks human evolution to try to show how many medical maladies today may have been responsible for the survival of our ancestors. In doing so he not only answers questions such as those above but also provides much dinner-party-worthy trivia. One is that Chinese doctors of yore diagnosed diabetes by observing whether their patients' urine attracted ants. More importantly, Moalem surmises that a diabetes-like condition may have been the body's way of surviving frigid temperatures at the onset of the Ice Age. High levels of blood sugar, a natural antifreeze, allowed some humans to survive the cold 13,000 years ago and reproduce, he posits, although these days diabetes is the result. Moalem presents his arguments in fascinating, although at times simplistic, fashion. As for the reason for the 'Asian flush'? Europeans coped with dirty water by purifying it through fermentation and producing alcohol, he writes. Asians, however, boiled it to make tea. Hence they now lack the enzyme that properly metabolises alcohol.