News / Africa

Longevity Traced to Grandmothers

 Anthropology Professor Kristen Hawkes says humans are distinct among primates when it comes to longevity. Credit: Lee J. Siegel, University of Utah
Anthropology Professor Kristen Hawkes says humans are distinct among primates when it comes to longevity. Credit: Lee J. Siegel, University of Utah

Multimedia

Audio
Joe DeCapua
In modern society, grandmothers are often called upon to babysit. But a few million years ago, when primate grandmothers first started doing that, they apparently had a major impact on human evolution. Scientists believe it’s a big reason why we live much longer than other primates. It’s called the “grandmother hypothesis.”


University of Utah Anthropology Professor Kristen Hawkes says humans are distinct among primates when it comes to longevity.

“One of the things that’s really different about us humans, compared to our closest living relatives, the other great apes, is that we have these really long lifespans. We reach adulthood later and then we have much longer adult lives. And an especially important thing about that is that women usually live through the childbearing years and are healthy and productive well beyond,” she said.

Other primates are not as lucky.

“In other great apes, females, if they make it to adulthood, they usually die in their childbearing years and they get to be old, frail and gray and less able to do all the things that we associate with getting old. Well, of course, it happens to all of us, but it happens slower and later to us compared to the other great apes,” she said.

Hawkes said climate change may have set things in motion by affecting food supplies. Savannahs started replacing forests in Africa.

“One of the things it did was restrict the availability of the kinds of things that little kids, little apes, can feed themselves on. So that meant that ancestral moms had two choices. They could either follow the retreating forests, or if they stayed in those environments, then they just would have to feed their kids themselves. The kids couldn’t do it,” she said.

So, if mothers decided to feed their offspring themselves they would not be able to give birth as often. They’d just be too busy finding food. Here’s where granny primate steps in to help.

She said, “It would also mean that older females, whose fertility was coming to an end, could now make a big difference in their fitness by helping their daughters feed those grandchildren. And that would mean that moms could wean earlier.”

The act of early babysitting had long-range effects.

“That whole array of changes could account for why we have longer adult lifespans. We age more slowly. We mature later. Our kids are actually dependent longer, but we wean them earlier than the other apes do. And that hypothesis has been on the table for a while,” said Hawkes.

The caring for their daughters’ offspring may have triggered genetic changes that allowed older females to live longer. Those changes were eventually passed down. Computer simulations show that chimps, who reached adulthood at age 13, lived another 15 or 16 years. But humans in developed countries, who reached adulthood at 19, generally lived another 60 years or more.

Hawks and her colleagues believe the lengthening of the lifespan happened pretty quickly in scientific terms – between 24,000 and 60,000 years.

“This combination of grandmothering and increased longevity go together. When there’s grandmothering that makes more grandmothers. And it makes longevity increase from an apelike range into a humanlike range,” she said.

The “grandmother hypothesis” had its roots in research done in the 1980s. Hawkes and anthropologist James O’Connell lived among the hunter-gatherer Hadza people in Tanzania. Older women in that community spent their day gathering food for their grandchildren.

Hawkes says grandmothering made us more socially dependent on each other and “prone to engage each other’s attention.”

You May Like

Photogallery Americans Celebrate Thanksgiving With Feasts, Festivities

Holiday traditions include turkey dinners, 'turkey trots,' American-style football and New York parade with giant balloons More

Video For Obama, Ferguson Violence is a Personal Issue

With two years left in term, analysts say, president has less to lose by taking conversation on race further More

Video Italian Espresso Expands Into Space

When Italian astronaut Samantha Cristoforetti headed for the ISS, her countrymen worried how she would survive six months drinking only instant coffee More

This forum has been closed.
Comment Sorting
Comments
     
by: A from: Colombia
October 30, 2012 11:21 PM
How did they compare the difference of the grandmothering behavior / lifespan between apes and humans? That would tell us more about the origin of the hypothesis that relate those variables.


by: S from: Uk
October 28, 2012 7:42 PM
How do you know that it was grandmothers who babysat and not grandfathers? You haven't presented any evidence. If the older females were tired from childbearing it was probably older males.

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
To Make A Living, Nairobi Street Vendors Face Legal Hurdles, Physical Violencei
X
Lenny Ruvaga
November 27, 2014 7:05 PM
The Nairobi City Council has been accused of brutality in dealing with hawkers in the Central Business District - in order to stop them from illegally selling their wares on the streets. Lenny Ruvaga has more for VOA News from the Kenyan capital.
Video

Video To Make A Living, Nairobi Street Vendors Face Legal Hurdles, Physical Violence

The Nairobi City Council has been accused of brutality in dealing with hawkers in the Central Business District - in order to stop them from illegally selling their wares on the streets. Lenny Ruvaga has more for VOA News from the Kenyan capital.
Video

Video For Obama, Ferguson Violence is a Personal Issue

Throughout the crisis in Ferguson, Missouri, President Barack Obama has urged calm, restraint and respect for the rule of law. But the events in Ferguson have prompted him to call — more openly than he has before — for profound changes to end the racism and distrust that he believes still exists between whites and blacks in the United States. VOA White House correspondent Luis Ramirez reports.
Video

Video Online Magazine Gets Kids Discussing Big Questions

Teen culture in America is often criticized for being superficial. But an online magazine has been encouraging some teenagers to explore deeper issues, and rewarding their efforts. VOA religion reporter Jerome Socolovsky went to this year’s Kidspirit awards ceremony in New York.
Video

Video US Community Kicks Off Thanksgiving With Parade

Thursday is Thanksgiving in the United States, a holiday whose roots go back to the country's earliest days as a British colony. One way Americans celebrate the occasion is with parades. Anush Avetisyan takes us to one such event on the day before Thanksgiving near Washington, where a community's diversity is on display. Joy Wagner narrates
Video

Video Aung San Suu Kyi: Myanmar Opposition to Keep Pushing for Constitutional Change

Myanmar opposition leader Aung San Suu Kyi says she and her supporters will continue pushing to amend a constitutional clause that bars her from running for president next year. VOA's Than Lwin Htun reports from the capital Naypyitaw in this report narrated by Colin Lovett.
Video

Video Mali Attempts to Shut Down Ebola Transmission Chain

Senegal and Nigeria were able to stop small Ebola outbreaks by closely monitoring those who had contact with the sick person and quickly isolating anyone with symptoms. Mali is now scrambling to do the same. VOA’s Anne Look reports from Mali on what the country is doing to shut down the chain of transmission.
Video

Video Ukraine Marks Anniversary of Deadly 1930s Famine

During a commemoration for millions who died of starvation in Ukraine in the early 1930s, President Petro Poroshenko lashed out at Soviet-era totalitarianism for causing the deaths and accused today’s Russian-backed rebels in the east of using similar tactics. VOA’s Daniel Shearf reports from Kyiv.
Video

Video Hong Kong Protests at a Crossroads

New public opinion polls in Hong Kong indicate declining support for pro-democracy demonstrations after weeks of street protests. VOA’s Bill Ide in Guangzhou and Pros Laput in Hong Kong spoke with protesters and observers about whether demonstrators have been too aggressive in pushing for change.
Video

Video US Immigration Relief Imminent for Mixed-Status Families

Tens of thousands of undocumented immigrants in the Washington, D.C., area may benefit from a controversial presidential order announced this week. It's not a path to citizenship, as some activists hoped. But it will allow more immigrants who arrived as children or who have citizen children, to avoid deportation and work legally. VOA's Victoria Macchi talks with one young man who benefited from an earlier presidential order, and whose parents may now benefit after years of living in fear.
Video

Video New Skateboard Defies Gravity

A futuristic dream only a couple of decades ago, the hoverboard – a skateboard that floats above the ground - has finally been made possible. While still not ready for mass production, it promises to become a cool mode of transport... at least over some surfaces. VOA’s George Putic reports.
Video

Video Falling Gas Prices Impact US Oil Extraction

With the price of oil now less than $80 a barrel, motorists throughout the United States are benefiting from gas prices below $3 a gallon. But as VOA’s Kane Farabaugh reports, the decreasing price of petroleum has a downside for the hydraulic fracturing industry in the United States.
Video

Video Tensions Build on Korean Peninsula Amid Military Drills

It has been another tense week on the Korean peninsula as Pyongyang threatened to again test nuclear weapons while the U.S. and South Korean forces held joint military exercises in a show of force. VOA’s Brian Padden reports from the Kunsan Air Base in South Korea.
Video

Video Mama Sarah Obama Honored at UN Women’s Entrepreneurship Day

President Barack Obama's step-grandmother is in the United States to raise money to build a $12 million school and hospital center in Kogelo, Kenya, the birthplace of the president's father, Barack Obama, Sr. She was honored for her decades of work to aid poor Kenyans at a Women's Entrepreneurship Day at the United Nations.
Video

Video Ebola Economic Toll Stirs W. Africa Food Security Concerns

The World Bank said Wednesday that it expects the economic impact of the Ebola outbreak on the sub-Saharan economy to cost somewhere betweenf $3 billion to $4 billion - well below a previously-outlined worst-case scenario of $32 billion. Some economists, however, paint a gloomier picture - warning that the disruption to regional markets and trading is considerable. Henry Ridgwell reports from London.
Video

Video Chaos, Abuse Defy Solution in Libya

The political and security crisis in Libya is deepening, with competing governments and, according to Amnesty International, widespread human rights violations committed with impunity. VOA’s Al Pessin reports from London.
Video

Video US Hosts Record 866,000 Foreign Students

Close to 900,000 international students are studying at American universities and colleges, more than ever before. About half of them come from Asia, mostly China. The United States hosts more foreign students than any other country in the world, and its foreign student population is steadily growing. Zlatica Hoke reports.

All About America

AppleAndroid