The animal kingdom is full of strange reproductive strategies, but when it comes to menopause, humans are among the weirdest. In just three species on the planet — humans, killer whales and pilot whales — do females routinely stop breeding years before the end of their lives. Human women spend about a third of their life span after menopause.
Seems counterproductive to stop having children so early in life when evolution is supposed to favor those with the most offspring, right?
Many species become less fertile as they age. For instance, female chimpanzees experience declining fertility rates from their early 30s onward until their reproductive chances reach zero around age 45. What makes humans and some whales different is that they carry on living and surviving with good odds for so long after menopause, whereas chimpanzees and other animals rarely survive much beyond the point where their eggs run out, even in captivity, said Virpi Lummaa, an evolutionary biologist at the University of Sheffield in England.
Posts
No comments:
Post a Comment
You only need to enter your comment once! Comments will appear once they have been moderated. This is so as to stop the would-be comedian who has been spamming the comments here with inane and often offensive remarks. You know who you are!