Many biologists believe menopause evolved because it gave human grandmothers more time to help care for their grandchildren, said Steve Austad, a researcher at the University of Texas Health Science Center in San Antonio who was not involved in the study.
The new findings argue against the so-called ''grandmother hypothesis,'' because female gorillas in the wild migrate away from their family groups and don't hang around to care for the grandkids.In other primate gender news, male and female vervet monkeys show the same preference for "gendered" toys as human boys and girls. One more data point in balancing nature and nurture.
And in other "smart animal" news, a humpback whale freed from entangling ropes by divers went around and nuzzled each diver before swimming off. Assuming the divers aren't exaggerating, it's hard to deny that the whale understood what the divers were doing, despite having no similar experience in the past, and at least showed affection. Concluding that it was attempting to communicate gratitude might be more than the evidence shows, although the evidence also leaves that possibility open.