This is a very complicated work, and I am not ashamed to say that some of it is beyond my level of understanding, as a person without a background in biology.
In this book Odent puts forward his contribution to the hypothesis that homo sapiens in descended from an aquatic ape. Further to the established features such as our hairlessness, fat layer under the skin, the height of our larynx etc, Odent explores more unusual features such as the fact that we share menopause with certain species of cetacean; that we have a layer of vernix at birth in common with seals; and our crucial need for nutrients such as iodine and omega three, that come readily from seafood. He also points to the fact that newborn humans can swim automatically if placed in water, and the relaxing effect of water, both through sight and touch, on our minds and bodies.
As well as discussing this theory about how homo sapiens have evolved to be the way they are, Odent points to our own time as a turning point in human evolution. We know that there are many events surrounding birth that can result in changes in our epigenetics, that are then passed down to future generations. The study of the microbial nature of birth has become very fashionable, and has been shown to affect our health for the rest of our lives. While many who are concerned with the birth microbiota focus on the difference between vaginal and caesarean birth, Odent states that we should be more concerned about the difference between home and out of home (hospital, birth centre) birth. He illustrates this fundamental separation by pointing to the fact that the human placenta transfers vast quantites of maternal antibodies to the foetus as the pregnancy approaches term, such that at 38 weeks gestation the concentrations are the same between mother and foetus, and the foetal levels continue to rise, meaning that a baby born at term has higher concentrations of maternal antibodies than the mother herself. This means that the immune system of the baby is already prepared to deal with the microbiome with which the mother's immune system is familiar: crucially that of the home,a and not the hospital. Odent also wishes us to focus on the differences resulting from in-labour and pre-labour birth, again rather than between vaginal and caesarean birth. It is thought currently that labour is triggered by the production of surfectants in the baby's lungs. This is a feature of the baby's development, and so labour starts when the baby is developmentally ready to be born. We know that babies born by pre-labour caesareans are at greater risk of various health problems. babies born by pre-labour caesarean go through a very different hormonal experience, and there are repercussions of this for the development of their brain and hormonal system. There are also repercussions for the mother, who is more likely to experience placenta praevia in future pregnancies, and who has experienced an altered operation of her own hormonal system.
This is a richly detailed and referenced book, and I am keen to find out what more knowledgeable experts than I have to say about it! Odent's perspective on our time as a turning point in our own evolution is both fascinating and terrifying. I look forward to seeing what he produces next!