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 and Professor Rachel Caspari from Central Michigan University believes was a turning point for . 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 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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More information: Scientific American

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Citation: Grandparents connected to success of human race (2011, July 26) retrieved 19 August 2019 from https://phys.org/news/2011-07-grandparents-success-human.html
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Jul 26, 2011
I thought this would be pretty obvious. I figured this out in high school when I tried to think of why people live so much longer than there ability to breed under the evolution. Since the information on how "much" longer they are going to live will not impact the fact that they have offspring. I came to a conclusion that the information that the older generation holds is valuable to the success of future generations. But data is king and I didn't have the training to do this type of research so Kudos.

Jul 26, 2011
I remember hearing about the "Grandmother effect" decades ago. This is not new, although now there is probably more data to support it.

Jul 26, 2011
In the age of the Internet, this may be a bad deal for grandparents. With all the world's information available at people's fingertips, who needs'em. By the way, I am one.

Dug
Jul 27, 2011
This theory of residual survival information has been around for a very long time. However, it has very indirect and minimal genetic affects which are far more likely to be overshadowed by climate change warming that allows for a more varied and complete diet - regarding extending life expectancy. You also have to understand that longer lives don't necessarily mean longer life span potential. It's very probable that we have the same life span potential as our ancestors did 100,000 years ago, but our life styles of better diet, reduced risks and the ability to treat fatal diseases has extended only the average number of years that we live. There are no direct genetic feed back/selection loops once reproduction occurs and whatever strengths or weaknesses are passed on. We are already seeing how rapidly weaknesses are passed in things like eye sight - which with advent of corrective lens - no longer exerts significant selection pressure on pre-reproducing populations.

Jul 31, 2011
Parents raise children.. grandparents teach their grandchildren what it is to be human.

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