https://www.theguardian.com/books/2020/apr/10/the-better-half-by-sharon-moalem-review-on-the-genetic-superiority-of-women

Women live longer than men. We know Covid-19 is killing more men than women. This book is an antidote to the myth of the ‘weaker sex’

Let’s hear it for the female of the species and (more guardedly) for her second X-chromosome! Female superiority in colour vision, immune response, longevity, even basic survival from birth to death are illustrated in Sharon Moalem’s The Better Half. After decades, if not centuries, of bad press for women and their vulnerable biology, this book argues that in fact “almost everything that is biologically difficult to do in life … is done better by females”.

Moalem, a Canadian-born physician, is a research geneticist who has identified two new rare genetic conditions. He has worked across the world in paediatric medicine, including clinics for HIV-infected infants and is also a biotechnology entrepreneur and bestselling author. The Better Half is his latest foray into the field of popular science, and presents a general argument for the superiority of women’s biology to men’s.

In most circumstances, a human female has two X-chromosomes, one from her father and one from her mother; a male has just one, inherited from his mother, which is paired with a Y-chromosome, inherited from his father. Moalem believes that the X-chromosome has always received a poor press, and that it is time this negative view is counteracted. He draws on swathes of medical and historical data to show that, in many instances, the superiority of women’s biology is explicitly linked to their possession of the second X-chromosome. The greater complexity of women’s biology, he claims, is the secret of their success – it is more difficult to make a female but, once made, she trumps the male in her lifelong survival skills, for instance in her hyperefficient immune system shrugging off infection and maximising the benefits of vaccination – which means that females can avoid the consequences of a wide range of life threatening events ranging from starvation and cancer to, Moalem has cautiously concluded, Covid-19.

In mainstream genetics it was long held that, despite having two X-chromosomes, female cells only made use of one: the second randomly switched off or deactivated early on in embryonic development, a process rather summarily described as an instance of “genetic redundancy”. There was some evidence that the deactivation reduced female chances of succumbing to X-linked problems, due to the availability of an undamaged back-up. It was acknowledged, for example (though rather grudgingly), that women generally escaped being colour blind. Moalem notes that when he was studying genetics there was much emphasis on the tiny Y-chromosome as “what makes a man”. He observes wryly that maybe this positivity was related to the fact that “most of the people who were speaking breathlessly about the Y had one as well”.