News / Science & Technology

Teeth May Hold Clues About Early Man's Weaning Patterns

FILE - The March 20, 2009 file photo shows reconstructions of Neanderthal men at the Neanderthal museum in Mettmann, Germany. Teeth of Neanderthal and early man may hold clues about Homo sapiens' evolutionary advantages over Neanderthal.
FILE - The March 20, 2009 file photo shows reconstructions of Neanderthal men at the Neanderthal museum in Mettmann, Germany. Teeth of Neanderthal and early man may hold clues about Homo sapiens' evolutionary advantages over Neanderthal.

Related Articles

Neanderthals Almost Extinct in Europe When Homo Sapiens Arrived

Finding suggest Neanderthals may have been more sensitive to dramatic changes in climate that occurred in last Ice Age than thought

Ancient Cave Art Could Be From Neanderthals

Markings in Spain are 40,000 years old

Neanderthal Genome Data Sheds Light on Human Ancestors

The DNA for the sequencing came from a toe bone found in a Siberian cave
VOA News
Scientists have long speculated that the early weaning of human babies gave homo sapiens an evolutionary advantage over Neanderthals. Now they may have discovered a way to prove the theory.

New research indicates that the level of barium measured in teeth corresponds with increased breastfeeding.

“People have speculated that an early weaning process in modern humans may have been part of their evolutionary advantage,” said Tanya Smith, an associate professor of human evolutionary biology at Harvard University in a statement. “We don’t have the data to answer that question yet, but we now have the method to be able to start collecting that data.”

According to the study, shorter nursing periods could have led to higher reproductive rates among modern humans.

By studying barium levels, “the timing of breastfeeding and the weaning process can be uncovered in tooth crowns – down to nearly the day,” according to the research, which was published in the journal Nature.

Teeth develop in a similar manner to trees, growing in regular layers made up of various minerals and small amounts of metals, like barium. By studying the barium levels in the layers of teeth, researchers were able to show that barium levels increase dramatically when breastfeeding begins and then fall off as infants begin eating a more varied diet.

Researchers first showed that barium levels correlate with breastfeeding using data from humans and monkeys whose infant diets were well documented.

“We can see when the barium shows up in the tooth after birth, and we see it increase over time, because an infant will take more milk as they get bigger and more active, and then you see it drop off in this beautiful, inverted U-shaped function,” said Katie Hinde, an assistant professor of human evolutionary biology at Harvard.

The methods for measuring barium levels could also be used on fossilized teeth.

“This is a game-changer in many ways, because this will allow us to go to museum collections and look at this as a proxy for how much milk different infants got from their mothers, and what their weaning process was like,” said Hinde. “We can now look at that within species, but we can also look at that among species.  That will tell us about the evolution of how mothers invest in their young.”

Smith adds that the research could lead to answers about other developmental differences between humans and Neanderthal.

“What does it mean that human and Neanderthal cranial development was different? What does it mean that their dental development was different? We haven’t been able to get at these questions in the fossil record, but now we can actually get at a real developmental benchmark. That’s why this is so exciting,” she said.

You May Like

Conflicts Engulf Christians in Mideast

Research finds an increase in faith-based hostilities, and Christians are facing persecution in a growing number of countries in the region More

Chinese Americans: Don’t Call Us 'Model Minority'

Label points to collective achievement, but some say it triggers resentment, unrealistic expectations More

Iran Bolsters Phone, Internet Surveillance

Does increased monitoring suggest the government is nervous? More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
West Africa Ebola Vaccine Trials Possible by Early 2015i
X
Carol Pearson
August 30, 2014 7:14 PM
A U.S. health agency is speeding up clinical trials of a possible vaccine against the deadly Ebola virus that so far has killed more than 1,500 people in West Africa. If successful, the next step would be a larger trial in countries where the outbreak is occurring. VOA's Carol Pearson has more.
Video

Video West Africa Ebola Vaccine Trials Possible by Early 2015

A U.S. health agency is speeding up clinical trials of a possible vaccine against the deadly Ebola virus that so far has killed more than 1,500 people in West Africa. If successful, the next step would be a larger trial in countries where the outbreak is occurring. VOA's Carol Pearson has more.
Video

Video Survivors Commemorate 70th Anniversary of Nazi Liquidation of Polish Ghetto

When the Nazi army moved into the Polish city of Lodz in 1939, it marked the beginning of a long nightmare for the Jewish community that once made up one third of the population. Roughly 200,000 people were forced into the Lodz Ghetto. Less than 7,000 survived. As VOA’s Kane Farabaugh reports, some survivors gathered in Chicago on the 70th anniversary of the liquidation of the Lodz Ghetto to remember those who suffered at the hands of the Nazi regime.
Video

Video Cost to Raise Child in US Continues to Rise

The cost of raising a child in the United States continues to rise. In its latest annual report, the U.S. Department of Agriculture says middle income families with a child born in 2013 can expect to spend more than $240,000 before that child turns 18. And sending that child to college more than doubles that amount. VOA’s Deborah Block visited with a couple with one child in Alexandria, Virginia, to learn if the report reflects their lifestyle.
Video

Video Chaotic Afghan Vote Recount Threatens Nation’s Future

Afghanistan’s troubled presidential election continues to be rocked by turmoil as an audit of the ballots drags on. The U.N. says the recount will not be completed before September 10. Observers say repeated disputes and delays are threatening the orderly transfer of power and could have dangerous consequences. VOA correspondent Meredith Buel reports.
Video

Video Ukraine Battles Pro-Russia Rebel Assault

After NATO concluded an emergency meeting to discuss the crisis in eastern Ukraine, the country is struggling to contain heavy fighting near the strategic port of Mariupol, on the Azov Sea. Separatist rebels are trying to capture the city, allegedly with Russian military help, and Ukraine's defense forces are digging in. VOA's Daniel Schearf spoke with analysts about what lies ahead for Ukraine.
Video

Video Growing Business Offers Paint with a Twist of Wine

Two New Orleans area women started a small business seven years ago with one thing in mind: to help their neighbors relieve the stress of coping with a hurricane's aftermath. Today their business, which pairs painting and a little bit of wine, has become one of the fastest growing franchises across the U.S. VOA’s June Soh met the entrepreneurs at their newest franchise location in the Washington suburbs.
Video

Video Ebola Vaccine Trials To Begin Next Week

The National Institutes of Health says it is launching early stage trials of a vaccine to prevent the Ebola virus, which has infected or killed thousands of people across West Africa. The World Health Organization says Ebola could infect more than 20,000 people across the region by the time the outbreak is over. The epidemic has health experts and governments scrambling to prevent more people from becoming infected. Zlatica Hoke has more.
Video

Video Asian Bacteria Threatens Florida Orange Trees

Florida's citrus fruit industry is facing a serious threat from a bacteria carried by the Asian insect called psyllid. The widespread infestation again highlights the danger of transferring non-native species to American soil. VOA’s George Putic reports.
Video

Video Aging Will Reduce Economic Growth Worldwide in Coming Decades

The world is getting older, fast. And as more people retire each year, fewer working-age people will be there to replace them. Bond rating agency Moody’s says that will lead to a decline in household savings; reducing global investments - which in turn, will lead to slower economic growth around the world. But experts say it’s not too late to mitigate the economic impact of the world’s aging populations. Mil Arcega has more.
Video

Video Is West Doing Enough to Tackle Islamic State?

U.S. President Barack Obama has ruled out sending ground troops to Iraq to fight militants of the so-called Islamic State, or ISIS, despite officials in Washington describing the extremist group as the biggest threat the United States has faced in years. Henry Ridgwell reports from London on the growing uncertainty over whether the West’s response to ISIS will be enough to defeat the terrorist threat.
Video

Video Coalition to Fight Islamic State Could Reward Assad

The United States along with European and Mideast allies are considering a broader assault against Islamic State fighters who have spread from Syria into Iraq and risk further destabilizing an already troubled region. But as VOA State Department Correspondent Scott Stearns reports, confronting those militants could end up helping the embattled Syrian President Bashar al-Assad.
Video

Video Made in America Socks Get Toehold in Online Fashion Market

Three young entrepreneurs are hoping to revolutionize the high-end sock industry by introducing all-American creations of their own. And they’re doing most of it the old-fashioned way. VOA’s Julie Taboh recently caught up with them to learn what goes into making their one-of-a-kind socks.
Video

Video Americans, Ex-Pats Send Relief Supplies to West Africa

Health organizations from around the world are sending supplies and specialists to the West African countries that are dealing with the worst Ebola outbreak in history. On a smaller scale, ordinary Americans and African expatriates living in the United States are doing the same. VOA's Carol Pearson reports.

AppleAndroid