Tag: human migrations

Clever Study Uses Genetics Trick to Trace Language Back to Its Very Beginning, in Africa

By Valerie Ross | April 15, 2011 2:47 pm

walking
Likely area of language origin, in white, based on:
A) phonemes found in individual languages and
B) phoneme diversity averaged across language families

What’s the News: Southern Africa may be the birthplace of human language, according a new study published yesterday in Science. The study further suggests that language may have arisen only once, with one ancestral language giving rise to all modern tongues, an idea linguists have long debated. This finding parallels the human migrations out of Africa supported by genetic and fossil evidence.

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CATEGORIZED UNDER: Human Origins

New Archeology Find Buries Theory on First Americans, Re-Opening a Gaping Mystery

By Patrick Morgan | March 25, 2011 5:06 pm

What’s the News: Archeologists have discovered thousands of stone tools in Texas that are over 15,000 years old. The find is important because it is over 2,000 years older than the so-called Clovis culture, which had previously thought to be the first human culture in North America. As Texas A&M University anthropologist Michael Waters says, “This is almost like a baseball bat to the side of the head of the archaeological community to wake up and say, ‘hey, there are pre-Clovis people here, that we have to stop quibbling and we need to develop a new model for peopling of the Americas’.”

How the Heck:

  • At a site on Buttermilk Creek in central Texas, Archeologists discovered 15,528 items, ranging from chert flakes to blades and chisels.
  • The first indication that the tools were older than anything previous seen on North America came from their stratigraphic horizon: The excavated layer was underneath a layer of classic Clovis tools. (The sediments showed no indication of mixing after the tools were dropped.)
  • The most conclusive evidence came from a dating technique called optically stimulated luminescence (OSL) dating, which indicates how long minerals have been underground. Over 60 OSL dates revealed the tools to be about 15,500 years old, much older than the up-to-13,500-year-old Clovis culture.

What’s the Context:

Not So Fast:

  • Some anthropologists say that the “Clovis first” theory went out of style years ago, and that this study only puts the nail in the Clovis coffin.
  • Others are skeptical about this present finding, noting that OSL dating is less reliable than radiocarbon dating and that the site’s deposits are “potentially problematic” because they’re located on an old floodplain and could have been transported by water.

The Future Holds: Now it’s time for archeologists to rethink the North American narrative of migration: How did humans first populate the continent? As James Adovasio, the executive director of the Mercyhurst Archaeological Institute, told NPR, “Everything we’re learning now, from genetics, from linguistic data, from geological data, from archaeological data, suggests that the peopling process is infinitely more complicated than we might have imagined 50 years ago, or even 20 years ago.”

Reference: The Buttermilk Creek Complex and the Origins of Clovis at the Debra L. Friedkin Site, Texas. By Michael R. Waters et al. DOI: 10.1126/science.331.6024.1512

Image: Courtesy of Michael R. Waters

CATEGORIZED UNDER: Human Origins

Tibetans May Be the Fastest-Evolving Humans We've Ever Seen

By Andrew Moseman | July 2, 2010 9:13 am

Tibetan_ladyClearly, the people of Tibet must have evolved quickly to tolerate a life spent living at the top of the world. How quickly? A study out in this week’s Science, which compared Tibetans to Han Chinese to see the differences in their DNA, says that the two groups may have diverged no more than 3,000 years ago. If natural selection has changed Tibetans in such a short time, it would be the fastest known example of human evolution. But not everybody is buying this time line.

As DISCOVER noted when a similar study by another team came out in May, natives of the Tibetan plateau seem to survive the altitude because their bodies make less hemoglobin. It’s somewhat counter-intuitive:

In theory higher levels of haemoglobin would be beneficial, because this would improve oxygen transport. But high levels could make the blood thicker and less efficient at carrying oxygen, says Jay Storz of the University of Nebraska-Lincoln [New Scientist]. (Storz writes the accompanying commentary in Science.)

Looking at the differences in genes that regulate that, the team found vast differences between the Han and the Tibetans, with one version appearing in 87 percent of Tibetans studied but only 9 percent of Chinese. However, the assertion by the scientists at the Beijing Genome Institute—that their findings mean the two group broke apart just three millennia ago—has ruffled archaeologists who believe that the Tibetan plateau has been continuously occupied for much, much longer: more like 7,000 to 21,000 years.

For more about all of this, check out Razib Khan’s post at Gene Expression.

Related Content:
Gene Expression: Very Recent Altitude Adaptation in Tibet
Gene Expression: Tibet & Tibetans, Not Coterminus
80beats: Found: The Genes That Help Tibetans Live at the Top of the World
DISCOVER: High-Altitude Determines Who Survives in Tibet

Image: Wikimedia Commons

CATEGORIZED UNDER: Health & Medicine, Human Origins

Global Warming Forces an Alaska Town to Relocate

By Eliza Strickland | April 27, 2009 3:42 pm

Newtok, AlaskaThe 340 residents of Newtok, Alaska will soon be among the first “climate refugees” in the United States. Global warming has battered the tiny coastal town: As average yearly temperatures rise, coastal ice shelves melt as does the permafrost on which the town sits.  The Ninglick River has overtaken the town as the ground level simultaneously sinks [Backpacker blog]. As a result, the town’s scattered buildings are connected by a network of boardwalks across the mud.

With the forces of nature arrayed against them, the townspeople have now voted to relocate their town to a new site nine miles inland, on higher ground by the river. “We are seeing the erosion, flooding and sinking of our village right now,” said Stanley Tom, a Yup’ik Eskimo and tribal administrator for the Newtok Traditional Council…. The U.S. Army Corps of Engineers has estimated that moving Newtok could cost $130 million. Twenty-six other Alaskan villages are in immediate danger, with an additional 60 considered under threat in the next decade, according to the corps [CNN].

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CATEGORIZED UNDER: Environment
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