This is a treat for anyone who is already convinced by the ideas of evolutionary biology (http://en.wikipedia.org/wiki/Evolutionary_biology) or wishes an introduction to them. Here is a question…Will people born in the 1990s in the developed world live as long as those born 60 years ago? The upward trend in life expectancy of the last century is set to reverse unless the lifestyle of young people dramatically improves according to the authors of this thought-provoking book. With the epidemics of obesity and diabetes in mind, the authors condemn the mismatch between intrinsic physiological capacities programmed in the womb and lifestyles that encourage consumption of excess calories without the physical demands of former times. Like Old Testament patriarchs, they urge us to ‘return to a different way of life’ and condemn the modern habitat (of our own construction), to which they say we have become poorly adapted. All this requires a lot of reference back to the paleolithic and hunter gatherer societies.
The heart of the book is predicated on David Barker’s well known idea that nutritional and other kinds of stress experienced by the foetus in the womb affect its developmental trajectory even after birth. Extensive investigations of laboratory mammals and human epidemiology indicate that the response to nutritional stress is a Faustian bargain. Protecting the development of the brain and reproductive behaviour can only be achieved at the expense of underdeveloped viscera that compromise health in later life, especially if the child’s nutritional experiences are better than the mother’s during pregnancy. The outcome is likely to be premature onset of type 2 diabetes, coronary heart disease and more. The embryo also responds to high maternal blood sugar and psychological stress through epigenetic modifications of genomic function that are expressed after birth. These ultimately cause premature age-related diseases.
The authors apply their ‘mismatch paradigm’ to a range of situations where cultural developments create new problems. These include the emergence of a long post-reproductive life and the tricky interval between sexual maturity and the time when adolescents are considered mature enough to to be independent in a highly complex society.
Other issues include breast-feeding, the effect of reproductive customs on cancer of the reproductive organs, the possibility of diets deficient in micronutrients and the advance of myopia provoked by excessive reading at an early age. This book conveys admirably for a non-specialist reader the implications to human biology of an interesting idea. One idea that is repeatedly defended is that the nature/nurture dichotomy is a false one. Instead, in reality, there is a continuous mutual causal influencing between genes and their environment.
272 pages in Oxford University Press
ISBN 978-0199228386