Human females usually go through menopause between the ages of 45 and 55, or through a variety of hormonal changes that are no longer able to conceive. But they are not the only ones in the animal kingdom that live after their reproductive years.
Scientists have long known that fertility and reproductive success of animals in a slow decline over the lifespan – a phenomenon known as reproductive aging. But for the most part, reproduction in animals continues to age, even to the point of death, albeit with reduced capacity.
In the last exams of primate species, scientists have found that people are the only recipients that do not die within a few years of "termination of fertility". This is true even when modern medicine and health are subtracted from the equation, because the study included hunter-gathering tribe data! Kung in the Kalahari Desert
In recent decades, however, numerous studies have found that menopause or "post-reproductive life span" – the phrase most commonly associated with the age of the last reproduction, given that changes in ovulation and hormones associated with menopause are difficult Measure in wildlife populations – occurs in a wide range of species. For example, Gupiah passes through the fishy version of menopause, judging by one study that found that fish had an average of 13.6 percent of their full life in the post-reproductive phase.
Even so, such "menopause" is quite common in fish, birds, mammals and invertebrates, he writes in a review of the theme published in the journal Trends in Ecology & Evolution . However, there is a warning that goes with this statement: For most species, animals do not live long after cessation of reproduction, and menopause is a circumstance that is related to captivity (as in the case of pups) and occurs only in some individual species, not in the whole type.
But there are some exceptions. Among the vertebrates, two types of tooth whites live long after menopause. The killer kittens are reproduced at the age of 12 to 40, but can live up to the nineties, while the white dolphin belts are replicated between 7 and 35 years of age and live after the age of 60.
There are also some insects in this selected group, such as ears Quadratus yoshinomiyai where adult females have prolonged post-productive life span and belong to colony colony defenses
From the evolutionary points of view, menopause is obvious strangeness, as it would be expected that individuals want to transmit their genes as long as possible. So why did menopause develop?
The prevailing theory of menopause is called the "hypothyroid". In short, she argues that females early replicate to help their children and grandchildren survive and continue to reproduce. This is definitely true for the orchid populations (killer whales), where older women are storages of ecological knowledge, especially when it comes to finding food – scientists have found that mothers raise the survival rate of their adult children, who have better reproductive success than they are older.
Interestingly, matriarchal elves are also vital to the community, but they do not go through menopause.
Here the difference lies in the way groups are grouped. Sons and daughters of whale killing remain in the groups in which they were born. Thus during the time, mothers have more and more kinship with their neighbors, which provides the motive to shift from reproduction to helping offspring, and provides further enhancement of the genetic heritage. In elephants, the sons leave the group where they were born, and the mothers have nothing more to do during the years.
Another key aspect of this story is a resource competition.
An orchid investigation has shown that in a situation where two generations of killing killers in the same group simultaneously reproduce, a younger generation of females has a 1.7-fold higher probability of death. This may be because younger females focus only on their young, while older females have to "raise" their own children and their adult daughter's children.
With ancient people, daughters would move out to join new families. In the beginning, the daughter would not have any kinship with the group until she was born, but to become older, she would increasingly associate with her group over time. In the end, helping your relatives to nurture children will also provide you with a genetic advantage, especially because a greater number of children put their new children into a resource competition directly with her other descendants.