Male-mediated maturation in a wild primate

Abstract

In humans, a controversial hypothesis suggests that father absence promotes early puberty in daughters. Data from rodents confirm females accelerate maturation with exposure to novel males (“Vandenbergh effect”) and delay it with exposure to male relatives. Here, we report the first case of male-mediated maturation in a wild primate, geladas (Theropithecus gelada). Females were more likely to mature after a change in the reproductive male: some matured earlier than expected (Vandenbergh effect) and some later (due to father presence). Novel males stimulated a surge in estrogens for all immature females - even females too young to mature. Although male-mediated puberty accelerated first births, the effect was modest, suggesting that alternative scenarios, such as co-evolution with the Bruce effect (male-mediated fetal loss) may explain this phenomenon.One Sentence SummaryNovel males induce an estrogen surge, male-mediated puberty, and a head-start on reproduction for immature female geladas.

Primate Reproduction: When Timing Is Everything

“…What is a female to do? The new study by Lu and colleagues 4 reveals one way that females can game this system. Observers assiduously tracked female reproductive maturation in multiple gelada units in Ethiopia's Simien Mountains National Park over a period of 14 years, observing 28 male takeovers.…”

“…Lu and colleagues 4 propose that social cues are cognitively processed, allowing the monkeys to evaluate a diverse array of information. This would make it less likely that female biology is simply being hijacked by a mechanism that benefits the male.…”

“…How does the brain generate this face space? Past research offered two, apparently contradictory, answers: one study found neurons that scale their response faithfully with changing facial features, thus establishing the axes of face space (axis coding) 4,5 . Another study found neurons that responded…”