Paul Griffith explains in a letter to Nature:
Nature’s recent Editorial and collection of opinion articles on sex and gender in research would have benefited from greater attention to evolutionary biology and the definition of sex by anisogamy, or differing gamete size. In the words of evolutionary biologist Joan Roughgarden in her book Evolution’s Rainbow (Univ. California Press, 2013): “To a biologist, “male” means making small gametes, and “female” means making large gametes. Period!”
This definition avoids the ‘sex binary’ that concerns so many people. Some organisms produce both male and female gametes, and others produce different gametes at distinct life stages or under various conditions. Organisms can be male, female, both at the same time, male at one time and female at another, or have no clear and unambiguous sex. The definition also implies that there are no essential or universal male or female phenotypes: male pipefish gestate their embryos and female jacana birds fight over mates, for example.
Anisogamy is at the heart of the modern theory of why sexes evolved and why they show such extraordinary diversity. Neglecting it makes the varied phenotypic expression of sex, and its interaction with gender in humans, seem unmanageably complex. As with so much of biology, sex makes better sense when viewed in the light of evolution.
Nature 631, 275 (2024)
doi: https//doi.org/10.1038/d41586-024-02248-1
