How Remour’s brain changes made some mean girls lovely

If there was a competition for the biggest female bullys in the animal world, the lemurs are at the top of the list. In these distant primate cousins, it is the women who call the shots, relying on physical attacks to follow the path and line up men.

However, not all lemurs are constructed about the rules of women. In one branch of the leshark family tree, several species have evolved within the last million years, and have become more harmonious relationships between genders.

Now, new findings suggest that this amiable change in bitches was at least partially promoted by altered actions of “love hormone” oxytocin in the brain.

In a study published in the Journal Biology Letters, researchers from Duke University studied seven closely related Lemur species in the genus Eulemur, pointing out which one has more egalitarian women.

Take a blue-eyed black lemur, for example. The woman gets her first dib at food and major rest spots. Slap, bite, chase, walk the path.

Their actions are not intense protections for mothers to defend their babies, said Christine Drea, Duke’s professor of evolutionary anthropology. The aggression of these women can be completely unprovoked simply to remind others who are in charge.

“Men make women preferential access to what they want,” Drea said.

Other species, such as collars, are more peaceful and egalitarian, with men and women sharing an equal state. “It’s like a uniform arena,” said Ally Schlock, the first author to earn his PhD. At Drea Lab.

The lemurs in this study died of natural causes some time ago, but the organization remained alive thanks to the banks of these endangered primate organizations, and were frozen in the Duke Lemur centre. Using an imaging technique called autoradiography, researchers mapped the brain-binding sites of oxytocin, a hormone involved in social behavior such as trust and bonding.

The results revealed an impressive pattern.

Researchers have found that recently evolved egalitarian species have more oxytocin receptors than other species, providing essentially more targets for oxytocin to act. The key difference was the amygdala, a brain area that is usually associated with emotions such as fear, anxiety, and anger.

The bisexual pattern suggests that egalitarian species achieve gender equality by reducing aggression towards others rather than increasing aggression to match female counterparts. Drea said.

The potential impact goes beyond lemurs, the researchers said. Brain oxytocin signaling problems are associated with aggression, personality disorders and autism in humans, rodents and other animals.

Next, the researchers plan to examine the link between hormone receptors and additional aspects of lemur social behavior.

“There’s much more we can learn from lemurs about how the brain regulates behavior,” Schlock said.