We often think of grandma as the fun, gentle part of the family. It is no wonder she is often called when a sitter is needed. However, it is believed that the overall evolution of humans is based upon grandmothers as they are a key element in longevity. It is called the Grandmother Hypothesis and believed to be why humans live longer lives than other primates. Professor Kristen Hawkes of University of Utah Anthropology has been involved with studies regarding such differences in overall life span.
In addition, such studies also indicate the importance of women being able to remain healthy and productive well beyond just their years of being able to have children. For example, among the great apes, the females often die during the period of time when they are able to have offspring. Those that don’t, often age quickly and they become too frail to do what they need to in order to survive. This type of process occurs in humans at a slower pace than it does for other primates.
The studies Hawkes has been involved with indicate that climate changes could be part of what affects this. The connection also has to do with available food resources. As the forests in African have been depleted and replaced by the Savannahs, it has made a huge impact on the longevity among the primates there.
They are restricted in terms of what they can access for food. This required the ancestral mothers to retreat into the forests or to stay in environments where they would be able to feed their offspring. Those that selected to stay in locations where they had to feed the offspring reproduced at a slower rate. They had to find food to care for the young they already had. This could have been when the grandmothers were asked to step in and help with the care of the offspring.
The older females could offer their assistance to the younger females. By helping out, the mothers would be able to have enough food for their young. It could also mean the fertile females would be able to wean the youngsters in less time. All of this is significant in the role of grandmothers and overall for humans to have longer life spans.
Since we mature later, we also age slower. Our children depend on us for a longer period of time. Yet we do wean them in less time than the apes do. Part of the Grandmother Hypothesis is that the role of caring for the offspring of their ancestors caused genetic changes so that the older females would have a longer life span.
