About the episode
Menopause does not occur in many animal species. In humans of course, in some whales and now it also appears to occur among wild chimpanzees. This is very special.
Researchers made the discovery after tracking and studying wild chimpanzees in western Uganda for decades. Thanks in part to taking a lot of urine samples from the animals’ habitats, they were able to see that fertility among females declined after the age of 30 and no more births were seen after the age of 50.
In many animals, fertility is related to life expectancy. If the female is no longer able to produce young, then in many animal species she is no longer biologically important to the survival of the species.
But in some species, women remain important even after they lose their fertility. They still provide care and advice based on years of experience and play an important economic role, which means they are still essential to the survival of younger generations. This is the novelty hypothesis.
But chimpanzee society is different from ours. Older females often live far away from their daughters and grandchildren, and no longer play any role in their upbringing. However, the females studied often live beyond their fertile years.
This has previously been seen in primates in captivity, but these animals have access to continuous nutrition and medical care. This would suggest that the wild chimpanzees studied may have been doing better than average – perhaps temporarily. It is also possible that we have never seen this before in the wild, because the animals never had the opportunity to grow healthy and old enough due to human actions.
The researchers are very excited about this finding because the data could help better understand why menopause occurs in nature and how it develops in humans. Who knows, maybe menopause in humans was previously given space due to favorable living conditions.
Read more about the research here: A UCLA researcher finds the first evidence of menopause in wild chimpanzees
