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Your grandmother’s help with raising you wasn’t
an accident: It was a biological and social necessity that
was needed to help you and your mother survive and have more
children.
Unlike most female animals that keep reproducing until they
die, women continue to live after menopause.
This evolutionary explanation sometimes referred to as the
"grandmother hypothesis" has stated that women live
beyond their ability to have children because the advantage
of helping their daughters give birth and raise their children
outweighs the advantage of being able to reproduce them.
Grandmothers, who are not busy feeding children, have more
time on their hands to help with the grandchildren seems to
suggest that natural selection favored menopause.
In a study, data was collected on 537 women, tracking the
families from 1702 to 1823, and studying the life span of
the women.
Results from the study showed that on the average, more children
were born with families whose grandmother was still living
when their children began having children. The results also
showed that more children survived when the grandmother was
around, lived nearby and was available to help with raising
the grandchildren.
Experts also discovered that social reasons explain that
once their children reached menopause and no longer could
have children, the grandmothers were more likely to die.
Research has also shown how much of an impact postmenopausal
women have on the reproductive success of their kids and survival
of their grandchildren.
American
Journal of Human Biology May-June 2003; 15(3): 380-400
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