Grandmothers extend life

Grandmothers extend children's life expectancy, according to a joint study by researchers from the School of Mathematics and Statistics at the University of Sydney and the Institute of Anthropology at the University of Utah. In their study, the scientists around Kristen Hawkes of the University of Utah confirm the so-called grandmother hypothesis.

29/10/2012

The grandmother hypothesis states that caring for women in the post-menopausal age significantly prolongs the life span of children. The researchers around Kristen Hawkes have now developed a mathematical simulation model, with which they could verify the hypothesis. Their results were published in the journal „Proceedings of the Royal Society B“.

Grandmothers with a positive influence on evolution
Life expectancy got in the computer simulation by the „Grandmothering“ („Begroßmütterung“) increases relatively quickly from a monkey-like to a human level, write Hawkes and colleagues. The mathematical simulation of human evolution has shown that „without the care of the grandmothers the simulated creatures have an average age of 25 years“ reached the statement of the US anthropologist. After 24,000 to 60,000 years of grandmother support, the life expectancy of the simulated people rose to 49 years in the course of evolution, „the same age as the hunters and gatherers“ reached, explained the expert. For the first time their computer simulation confirmed the so-called grandmother hypothesis, write Hawkes and colleagues. The researchers assume that the life expectancy of the grandchildren was greatly influenced by the contribution of the grandmothers to the education, care and nutrition of the offspring.

Grandmother's hypothesis plausible explanation for the increasing life expectancy
The grandmothers make a significant contribution to the rearing of the offspring and are likely to trigger the switch from an independent rearing to monkeys pattern to a rearing of dependence and help according to human model according to researchers. With correspondingly positive effects on life expectancy. In their simulation model, scientists explicitly did not consider the approaches of competing theories, according to which the development of brain capacity should be responsible for the increasing life expectancy of humans. The computer simulation has proven that "an extension of the lifespan can be observed even in the exclusion of factors such as larger brains or the improved learning skills," the researchers write in the article „Increased longevity develops from Grandmothering“. (Fp)

Picture: Albrecht E. Arnold