July 26, 2011 report
Grandparents connected to success of human race
(PhysOrg.com) -- If you looked around at your family some 40,000 years ago, you would not have seen grandparents as the likelihood of a person passing their 30th birthday was slim. However, according to new research reported in Scientific American, 30,000 years ago things began to change and the life expectancy of adults began to rise.
It is this change that anthropologist and Professor Rachel Caspari from Central Michigan University believes was a turning point for human civilization. At the same time humans were living longer, evidence shows that there was an increase in food production, artistic expression, and the creation of complex weapons and tools and the researchers contribute this to the experience of the older members of the population.
The researchers looked at teeth from ancient human beings to determine the age they were at death. Throughout evolution, finding those that had lived past the age of 30 was rare. However, this changed when the researchers looked at Homo sapiens and compared them with Neanderthals. They discovered that for every 10 Neanderthals that had died at a young age, four adults survived past the age of 30. The striking difference was in the Homo sapiens where they discovered that for every 10 youngsters that died, 20 adults had reached the age of 30 or older.
The effects of having an increasingly older and more knowledgeable population, the researchers believe, were the key to the survival and success of the Homo sapiens. Elder members were able to pass down the information they had learned such as foods that were poisonous and tool making skills. Elder members of the community were able to care for children while others worked to provide and gather food.
While researchers do not know why it is that adults of this time began to live longer, they believe the change and the addition of older members was essential for survival.
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