Here’s a question that female animals coming of age in the wild (and perhaps elsewhere) must cope with: How do you make sure you don’t have sex with your father?
Humans have DNA tests and Maury. Less complex mammals have evolved other ways to combat this potential breeding snafu.
A new study published in the journal BMC Ecology provides evidence that female grey mouse lemurs, small-brained foraging primates from Madagascar, have evolved to be able to identify — and avoid — the mating calls of their absentee dads.
The males of this species vamoose soon after sexual consummation–and one litter might have several fathers. There’s no child support or visitation rights. But their dads do call. Specifically, the males have two calls, a mating call and an alarm call, and each call has certain flourishes.
According to the paper, “We found that male grey mouse lemur advertisement calls, but not alarm calls, contain acoustic patrilineal signatures. Furthermore, females paid more attention to the unrelated attention to the unrelated males’ advertisement calls than those of their fathers. Though the females were not in estrous at the time, this increased attention to unrelated males suggests that such discrimination may be an important mechanism for inbreeding avoidance.”
Because of the males’ lack of interaction with their young, the paper posits that the society has the necessity for this kind of communication because of the lack of “familiarity-based mechanisms often seen in more gregarious species with cohesive foraging groups.”
You see, lemurs are largely solitary but never move very far from home. The males stay in the neighborhood, which means they likely have little girl lemurs all over the place. They do travel some–they might go to the town next door — but the females don’t ever go that kind of distance. So, the dude lemurs are likely to circle back at some point when their girls have…blossomed.
Lead author Sharon E Kessler says: “Given that more complex forms of sociality with cohesive foraging groups are thought to have evolved from an ancestral solitary forager much like the mouse lemur, this suggests that the mechanisms for kin recognition like those seen here may be the foundation from which more complex forms of kin-based sociality evolved.”
Complex forms of kin-based sociality! LIke the Kardashians.
As much larger brained lemur-type animals, we also harbor some vestige of this talent. According to a 1979 study published in Infant Behavior and Development, Cheryl J. Brown, a researcher at the University of Toledo, showed that girl babies displayed a tendency to respond to the sound of their father’s voice more than to stranger male’s voices.
The amount of vocal reaction of four-month-old infants to the actual voices of their parents was compared with their reaction to the voices of same-sex strangers. Results showed that infants discriminated both of the parents’ voices from that of a stranger, but whereas the mother’s voice was associated with a nonsignificant increase in infant vocalization, the father’s voice was associated with a significant suppression of vocalization. Over-all, girls showed greater discrimination between the voices than did boys.
One could interpret this not so much as an evolutionary signal indicating “don’t sleep with your dad when he comes lurking around your mama’s woodland treehole,” and more of a “don’t even talk to your father when he comes seeking court-sanctioned visitation.” Protecting the child from procreating with that scumbag isn’t the issue. For now.
Oh, if only we could all be lemurs.