Congratulations to Molly Fox who has today published a first author article titled ‘Grandma Plays Favourites: X-Chromosome Relatedness and Sex-Specific Childhood Mortality’ in the Proceedings of the Royal Society B.
The paper – summaried below – has been picked up by nespapers internationally, including articles in The New Scientist, The Daily Mail, The Telegraph,The Independent, Science Now, ABC News Australia, ABC Science, Courier Mail, The New Zealand Herald, The Times of India, India Express, Daily News & Analysis India, Hindustan Times, CBC News, Irish Sun, Jezebel and Marie Claire
Why did post-menopausal longevity evolve in humans? According to the “Grandmother Hypothesis,” post-menopausal women can increase their genetic contribution to future generations by increasing the survivorship of their grandchildren. While some demographic studies have found evidence for this, others have found little support for it. We suggest that maternal and paternal grandmothers have different incentive to invest in grandsons and granddaughters, due to differences in genetic relatedness. Boys and girls differ in the percent of genes they share with maternal versus paternal grandmothers because of differences in X-chromosome inheritance. We have re-evaluated data from seven populations, and found that grandmothers’ effect on grandchildren varies according to their X-chromosome relatedness. This pattern may have influenced the evolution of our species, and could explain features of kin investment, fertility and mortality rates, residence patterns, and longevity.