Americas Settled by Two Groups of Early Humans, Study Says

Americas Settled by Two Groups of Early Humans, Study Says

Brian Handwerk
for National Geographic News
December 12, 2005

At least two distinct groups of early humans colonized the Americas, a new study says, reviving the debate about who the first Americans were and when they arrived.

Anthropologists Walter Neves and Mark Hubbe studied 81 skulls of early humans from South America and found them to be different from both modern and ancient Native Americans.

The 7,500- to 11,000-year-old remains suggest that the oldest settlers of the Americas came from different genetic stock than more recent Native Americans.

Modern Native Americans share traits with Mongoloid peoples of Mongolia, China, and Siberia, the researchers say.

But Neves and Hubbe found that dozens of skulls from Brazil appear much more similar to modern Australians, Melanesians, and Sub-Saharan Africans.

Neves and Hubbe describe their findings in this week's edition of Proceedings of the National Academy of Sciences.

Who Was First?

The scientists examined 81 skulls unearthed over many decades in Brazil's Lagoa Santa region. They represent the largest collection of early American remains, many of which had to be tracked down in European museums.

These "paleoamerican" or "paleoindian" skulls feature projecting lower jaws, broad noses, and broad eye sockets, the researchers report. These traits are unlike those of modern Native Americans.

This strongly suggests that those early Americans were in fact a distinct group, Neves says.

He adds that the group could have crossed the Bering Strait land bridge—the once-exposed landmass between Siberia and Alaska—thousands of years earlier than the Siberian populations who are believed to be the ancestors of modern Native Americans.

Other paleoamerican skulls have displayed similar traits to the Lagoa Santa skulls, which has led to controversy and differing theories about how and when the Americas were settled.

"I don't want people to think that we are proposing any kind of transoceanic migration from Africa or Australia," said Neves, of the University of São Paolo in Brazil.

"We know that these [paleoindian] people had reached China around 20,000 years ago. The Mongoloid population that you see in [northeast] Asia today is more recent. So we don't have to think about transoceanic migrations to explain this."

Genetic Drift

Recent genetic studies of modern human populations have also suggested multiple early migrations across the Bering land bridge.

Neves and colleagues have not been able yet to extract ancient DNA from the Lagoa Santa remains—but excavations are yielding additional ancient remains.

"We have already found at least 20 new skeletons older than 8,000 years that are not part of our paper," he said.

Still, not all scientists are convinced that the variations found in the skulls are proof of multiple migrations to the Americas.

"There is a huge amount of variation among the first Americans, more than you see among any other population outside of the Pacific," said Joseph Powell, an anthropologist at the University of New Mexico in Albuquerque.

"Much of that is genetic, and it comes from the fact, I think, that these first Americans had very small colonizing populations, and they have a great degree of genetic variation due to genetic drift."

Genetic drift describes random variations in a group's genetic makeup. Small populations are especially prone to the phenomenon, because the genes of a single individual play a proportionately larger role in successive generations.

American Theories

For decades most scientists believed that the first Americans were a group of hunters, known as the Clovis people, who entered the Americas via the Bering land bridge some 11,000 to 12,000 years ago.

"I think it has become more widely accepted in the archaeological community that people were here prior to Clovis," said Michael Waters, director of the Center for the Study of First Americans at Texas A&M University in College Station.

Sites in Siberia have shown that people lived in the harsh region on the Asian of the land bridge as early as 27,000 years ago, he added.

"People could survive in that Arctic environment and survive quite well," Waters said. "There would be nothing to stop them from heading east into present-day Alaska."

Moreover, sites like Chile's Monte Verde, where tools have been dated to 12,500 years ago, have bolstered the theory that people were in the Americas before the Clovis period.

"If you look at the time periods when people could have come over by land, it must have been very late, just before Clovis, or prior to the ice sheets that formed over North America reaching their maximum extent around 20,000 years ago," Waters said.

Yet the land bridge theory no longer holds a scientific monopoly.

Some scholars favor coastal migration theories, in which early settlers hopped along the Pacific coast in boats.

More controversial theorists won't rule out the possibility of ocean crossings from Europe or Africa.

However those first Americans arrived, the remains they left behind may be the only clues that could someday tell their story.

http://news.nationalgeographic.com/news/pf/35168552.html

 

Such places as Easter Island and other Islands between South America and Australia have been long susspected of being the stepping stones between Australia and the South American Continent.

What is the basic lesson here to be learned?

Humanity has been around a VERY LONG TIME....and our ancient ancestors existed at least 5 Million years ago.

AboveAlpha

 

Yes. humans have been around a lot longer than we ever knew... and the dates keep pushing back..

There is a series on PBS called Wild Indonesia that is just stunning .. New islands .. varied species.. and an amazing habitat and environments for evolution.

http://www.pbs.org/wildindonesia/

 

Yes....isolated islands such as some in Indonesia and like the Galapagos Islands where Charles Darwin visited....are perfect examples of how both Environment and Species Isolation will direct such island existing species EVOLUTION.

AboveAlpha

 

I never knew there were 17,000 islands in shallow seas. Its just a remarkable program.

http://www.pbs.org/wildindonesia/world/index.html

 

What many people don't realize is that many of the major islands existing in the Pacific are populated by AMERICAN CITIZENS....as there are a huge number of Islands and Chains of Islands such as American Samoa, Guam, Hawaii of course, Mariana's....etc....that are Territories of the United States.

These Island residents are American Citizens just as are Puerto Rican's, the U.S. Virgin Island's...etc.

There are so many U.S. Island Territories it would take this whole forum page to list them all.

AboveAlpha

 

I had no idea...............

 

Many people do not know this as well many people don't realize this is one of the major reasons why the United States has such a vast and powerful Navy in the Pacific as well as in all other oceans on the planet.

AboveAlpha

 

I like the idea that Clovis culture came from Europe -
The Clovis point has similarities to those found in Europe while Asiatics were placing small pieces of sharp materials into a shaft rather than a single stone point.


Moi

No ​

 

By "ancestor" you mean...? Most of our ancestors were not mammals.

 

It is unfortunate we have very little to go on regarding paleo Polynesians.
Obviously they did not grasp ocean voyages of thousands of miles without stepping stones.
I imagine those stepping stones being the Southern Hemisphere's Ice Age & the associated icebergs.
As things warmed up they slowly acquired the skills to read "ocean signs".
I like "reverse engineering" stone age times to grasp, they could not have been that "stupid".
I do believe they were in the Americas before the Asiatics and were of lesser numbers and possibly just wiped out, genocide style.
A last remaining population of this genome was on Tierra del Fuego (southern tip of S. America) .


Moi

No ​

 

No icebergs in the tropical pacific, and, no land bridge further east that the Philippines.

Try again.

 

Actually when it comes to Polynesians, we have a fairly good idea of how, when and where they went- because among other things they were fairly recent colonizers.

As I recall, the best evidence we have right now suggests that proto-polynesians originated from Taiwan, and expanded throughout the islands of the SW Pacific, and then gradually expanded beyond- among the later colonizations were Hawaii, Easter Island and New Zealand- oh and Madagascar I believe- which surprised me when I found out.

The Polynesians were certainly good enough sailors to have sailed to the Americas- after all they reached both Hawaii and Easter Island- but assuming that they did indeed go stepping stones they would have arrived after the first American colonizers.

Unless you are suggesting that the proto-polynesians who colonized Taiwan also went North and around the Siberian/Alaskan island route but I haven't seen anything to suggest that.

 

interesting but there's nothing to back it up, similar ideas do spring up independently...

 

but as of now any evidence for pacific island route is of a relatively recent contact...some suggest much earlier but it's unproven at this point...

 

then there would very old evidence of their occupation of the south pacific and there isn't any,none...they only reached Easter Island and Hawaii about 800yrs ago...

 

my daughter and anthropologist told me of a site in S America where there were chicken bone remains, Polynesian chickens, and chickens don't fly...and of the sweet potato a plant native to the americas found across Polynesia before European explorers arrived...circumstantial but compelling...

 

Not a chance.

The Polynesians relied on the fact the wind and currents occasionally switched directions at different times of year. So sometimes they could only sail east to west other times west to east. They could not accomplish a voyage to the Americas before this would change back, so basically they would have sailed back and forwards till they die

 

Chances are the winds were favorable at some point in the last 10,000 yrs.

"Recent maternal mitochondrial DNA analysis suggests that Polynesians, including Samoans, Tongans, Niueans, Cook Islanders, Tahitians, Hawaiians, Marquesans and Māori, are genetically linked to indigenous peoples of parts of Southeast Asia including those of Taiwanese aborigines. This DNA evidence is supported by linguistic and archaeological evidence.[1] Recent studies into paternal Y chromosome analysis shows that Polynesians are also genetically linked to peoples of Melanesia.[2] However the "out of Taiwan model" has been recently challenged by a study from Leeds University and published in Molecular Biology and Evolution. Examination of mitochondrial DNA lineages shows that they have been evolving within Island Southeast Asia (ISEA) for a longer period than previously believed. Polynesians arrived in the Bismarck Archipelago of Papua New Guinea at least 6,000 to 8,000 years ago and modern Polynesians are the result of a few Austronesian seafarers mixing with Melanesians.[3] The population migrations were most likely to have been driven by climate change — the effects of the drowning of a huge ancient peninsula called ‘Sundaland’ (that extended the Asian landmass as far as Borneo and Java). This happened during the period 15,000 to 7,000 years ago following the last Ice Age. Oppenheimer outlines how rising sea levels in three massive pulses caused flooding and the submergence of the Sunda Peninsula, creating the Java and South China Seas and the thousands of islands that make up Indonesia and the Philippines today"

http://en.wikipedia.org/wiki/Polynesian_culture

 

lack of facts is not an issue for Moi..

 

I have heard both stories and last I remember there hasn't been a satisfactory explanation for either.

Certainly would have been possible that a few Polynesian trips made it to the Americas, but Polynesians as far as I know didn't settle in any lands that were already occupied- Australia for example.

Perhaps they traded with Native Americans, or perhaps they became assimilated.

 

it took about 2K years for Polynesians to expand from the Fiji to Easter island the most eastern settlement... and Easter Island is still 2-3K kms from south america about the same as the shortest distance across the atlantic ocean, that's a considerable distance even for sailors as good as the Polynesians...there is no evidence for that level of open water technology for the time period (12K+ years ago) as Moi believes...

here is a link to the chicken bone discovery, unless the DNA samples were contaminated it suggests Polynesian contact around 600-700 yrs ago, and offers explanation for the sweet potato's cultivation in Polynesia... http://archive.archaeology.org/0801/topten/chicken.html

it would've been extremely difficult for the Polynesians in tiny numbers to have established a foothold in a well populated S America...

 

Excuse me?

How have you come to this?

AboveAlpha

 

Seriously?