Current ecology, not ancestral dispersal patterns, influences menopause symptom severity

All human females who reach midlife experience menopause, however, it is currently unclear why women experience this period of infertility, and why it is accompanied by many unpleasant symptoms. Using primary data from four ethnic groups in China, we test an existing theory that age of menopause and its symptoms are the result of intragenomic conflict between maternally and paternally inherited genes, with the outcome of such conflict predicted to be contingent on the ancestral post-marital residence pattern of the female (Úbeda et al., 2014). The model predicts that being ancestrally patrilocal results in less intragenomic conflict, causing a shorter, less symptomatic peri-menopause that terminates in a later menopause. Our findings show no support for this hypothesis, and suggest current, rather than ancestral, residence patterns better predict aspects of the menopausal transition. Furthermore, current patrilocality when compared to duolocality is associated with more severe menopause symptoms, which may be due to sexual, rather than intragenomic, conflict.