Posted on 08/08/2007 9:17:01 AM PDT by BGHater
Europe's first early human colonizers were from Asia, not Africa, a new analysis of more than 5,000 ancient teeth suggests.
Researchers had traditionally assumed that Europe was settled in waves starting around two million years ago, as our ancient ancestors—collectively known as hominids—came over from Africa.
But the shapes of teeth from a number of hominid species suggest that arrivals from Asia played a greater role in colonizing Europe than hominids direct from Africa.
These Asian hominids may have originally come from Africa, the scientists note, but had evolved independently for some time.
(Related: "Did Early Humans First Arise in Asia, Not Africa?" [December 27, 2005].)
"Asia was also an important center for hominid speciation," said Maria Martinón-Torres, a scientist at the National Research Center on Human Evolution in Burgos, Spain, who led the study.
The finding suggests that the hominid family tree could be much more complex than previously thought (explore an interactive atlas of human migration).
Genetic Safe
Species from the genus Australopithecus and the genus Homo arrived in Europe between two million and 300,000 years ago.
Until recently, a lack of fossils from this time period had made it difficult to piece together hominid evolution and migration patterns.
But using the latest fossil findings, Martinón-Torres and colleagues were able to examine more than 5,000 teeth from two-million-year-old Australopithecus and Homo skeletons from Africa, Asia, and Europe.
The shape of the teeth offered clues about each species' genetic lineages.
"Teeth are like the safe-box of the genetic code," Martinón-Torres said.
That's because—compared to bones—teeth change shape very little once they are formed, and their shape is strongly influenced by genetics.
The researchers classified each of the teeth using more than 50 indicators, such as fissure patterns, overall size, and length-to-width ratio.
"We looked at the entire landscape of the teeth—the mountains, valleys, ridges—everything," Martinón-Torres said.
What they found is that European teeth were more similar to Asian teeth than they were to African teeth.
However, the results don't rule out African influence on European genes.
"This finding does not necessarily imply that there was not genetic flow between continents," Martinón-Torres and colleagues write in their paper, "but emphasizes that this interchange could have been both ways."
The work will be published in tomorrow's issue of the Proceedings of the National Academy of Sciences.
Fluid Migrations
Rather than a one-way stream of people coming from Africa, Martinón-Torres and colleagues think there must have been a more fluid pattern of migrations.
"Just because people had come out of Africa didn't mean that they couldn't turn around and go back again," she said.
The researcher also believes that climate, food, and geography were major influences on hominid migration patterns.
The Sahara, for example, presented a big barrier for movement out of Africa and directly into Europe (see photos and read a related feature about athletes who ran across the Sahara earlier this year).
Rather than struggling across the Sahara, it appears that human ancestors spread in many directions before arriving in Europe.
Erika Hagelberg, a geneticist from the University of Oslo in Norway, is impressed with the study, but cautious about how it should be interpreted.
"The study shows that the genetic impact of Asia on Europe is stronger than that of Africa. But the teeth can't tell us the direction or the time when people migrated," she said.
Nonetheless, the new study does complement direct gene studies and supports the idea that hominids evolved independently in many different parts of the world.
"The fossil teeth are a way to study the traits of past peoples," Hagelberg said, "and help balance the work being done on the genes of people alive today."
So, it appears this deals with ancestors, and is not really relevant to the out of Africa theory as to Homo Sapiens.
It is my understanding that teeth change shape due to factors such as age, diet, pathological conditions including diseases and invading bacteria. Could someone clarify this please? For example, say there was a drought that killed a lot of vegetation, diet changes to meat.
By the condition of the teeth pictured, I almost assumed we came from Britain...(j/k my fellow Brit FReepers) :)
Somewhere along the line, Kate got sidetracked with thoughts of migration routes. The article is based on differences in teeth but she failed to mention what the differences were.
If there are differences in teeth between Africans and Eur/Asians, what are those differences?
Well put. The multiregionalist view is that humans came from Africa, very long ago, then diversified; the Replacement hypothesis is that something called anatomically modern humans originated only in Africa, sat there for a long while, then about 50,000 years ago exploded across the globe, not stopping until reaching Tierra del Fuego perhaps 10,000 years ago. “Out of Africa” is now a vague term which is often used as a prop for Replacement.
Humans are omniverous, and that is the case with the fossil forms purported as human ancestors.
that’s a lot, lot, lot
later.
Now that is amazing. I want to look into this much more because now I am curious.
Yup. Linked below: (This article from the NG is linked in post #19 in the below article)
Study points to larger role of Asian ancestors in evolution (challenging "Out of Africa" theory)
Ah!
North of iran between the black and caspian seas.
They'll eventually figure out that Adam & Eve that we all descended from went back to Africa from Asia....and, then left again later, IMO.
Today, everyone outside of Africa are more related to themselves that they are to anyone in Africa.
I can definitely see the links in many cultures. Asian (Mongolian, Chinese etc), Eskimos, Native American, and African American.
I have a good friend who traveled to China for missionary work. She is Black and some mistook her for Asian. Yellow skin, almond eyes.
Yeah, I know.
So that’s in Asia, correct? So where’s the news?
No, actually I think the caucasus mountains are considered the southern boundary line between europe and asia. South of the mountains is asia. North of the mountains is europe. The eastern boundary is the ural mountains and the ural river.
When I was in gradeschool, I had a teacher that claimed the atlas mountains in africa were the southern boundary of western europe...in otherwords, the northern coastlines of morocco and algeria were a sliver of europe. Since that was what I was first taught, that’w what I grew up believing. As an adult, I’ve yet to meet anyone that has ever been taught this as I was.
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