This discovery has led some biologists to argue that there was no selection for or against menopause at the time at which the ancestor of all modern humans lived in Africa, suggesting that menopause is instead a random evolutionary effect of a selection shadow regarding aging in early Homo sapiens. It is also argued that since the population fraction of post-menopausal women in early Homo sapiens was so low, menopause had no evolutionary effect on mate selection or social behaviors related to mate selection. Adaptive hypotheses
"Survival of the fittest" hypothesis
This hypothesis suggests that younger mothers and offspring under their care will fare better in a difficult and predatory environment because a younger mother will be stronger and more agile in providing protection and sustenance for herself and a nursing baby. The various biological factors associated with menopause had the effect of male members of the species investing their effort with the most viable of potential female mates.A problem with this hypothesis is that, if true, we would expect to see menopause exhibited among many species in the animal kingdom, and another problem is that in the case of extended child development, even a female who was relatively young, still agile, and attractive when producing a child would lose future support from her male partner due to him seeking out fertile mates when she reaches menopause, while the child is still not independent.
Gradual senescence is exhibited by all placental mammalian life histories. Menopause has been observed in several species of nonhuman primates, including rhesus monkeys and chimpanzees. Some research suggests that wild chimpanzees do not experience menopause, as their fertility declines are associated with declines in overall health. Menopause also has been reported in a variety of other vertebrate species including elephants, short-finned pilot whales, orcas, narwhals, beluga whales, and the guppy. However, with the exception of the short-finned pilot whale, killer whale, narwhals, and beluga whales, such examples tend to be from captive individuals, and thus they are not necessarily representative of what happens in natural populations in the wild. Dogs do not experience menopause; the canine estrus cycle simply becomes irregular and infrequent. Although older female dogs are not considered good candidates for breeding, offspring have been produced by older animals. Similar observations have been made in cats. See also
European Menopause and Andropause Society
Menopause in the workplace
Menopause in incarceration
Pregnancy over age 50

References
External links

Menopause: MedlinePlus
Menopause and Menopause Treatments