DNA Haplotypes
Forty-four occurrences of D4h3 mtDNAs were discovered in the database, including one from Shandong Province in China. Researchers recognized that D4h3 has two branches, one in China (D4h3b), and one in the Americas (D4h3a). The American one is found in Native Americans from the California coast, Mexico, and Chile.
Eleven occurrences of X2a were discovered in the database, and additional 26 occurrences in a specialized Ojibwa sample collection accessed for this project. These haplotypes turn up in people who are from the Great Plains and Great Lakes region of North America.
Implications
What the distribution implies is that the two populations were different—not very different, of course, just enough to suggest that the geographic groups were related to one another—and both entering from Beringea about the same time, after the Last Glacial Maximum about 15,000-17,000 years ago. The paths taken by the two groups were different—one down the ice free corridor into central Canada and one along the Pacific coast, rapidly reaching Tierra del Fuego.
I'm over simplifying. The paper doesn't rule out more migrations, in fact it suggests that, given the distribution of other mtDNA genes in Native American populations, it appears as if the entry into the continents was very much a stop-and-start process as the fluctuating climate allowed entry along either pathway. However, for sure, the paper gives more credence to the Ice Free Corridor being open and viable as an entry way than I've seen in a while.
Sources and Further Information
- The Population of America
- Bering Strait Land Bridge
- Pacific Coast Migration model
- Ice Free Corridor
- Last Glacial Maximum
- As of this moment, the paper is free to download from the Current Biology homepage.
- Perego, Ugo A., et al. 2009 Distinctive Paleo-Indian Migration Routes from Beringia Marked by Two Rare mtDNA Haplogroups. Current Biology 19:1–8. Free download
Comments
Has there not been evidence that one path lead from Europe along the ice to North America during the last glacial period ? Finds of skulls and skeletal remains that are non-siberian would suggest this to have taken place.
There is no evidence to support migration from Europe along the north over the ice. A new book is coming out by Stanford that is supposed to reveal new evidence, but so far it is all circumstantial and can be explained by independent invention. There is some possibility, however, of colonization from Oceania, although that evidence is also very limited.
I love the subject of migration into north America. Do you have any theories on entering from the upper east coast. I am 78 and all ways loved this subjectan education. High School ,thats it..thank you John A Stinson.
Well, speaking personally, I don’t buy it. At the moment, the evidence just is not there for trans-Atlantic crossings until the Vikings in the 11th century AD. That could always change if solid data comes in–you shouldn’t bury your head in the sand against real hard data–but as to what’s been published and I’ve had access to: no pre-Viking Atlantic crossings.
Kris
what if…? what if migration began from the americas outward?
Well, for sure, the preDorset culture got from Canada eastward to Greenland by about 4500 years ago.
http://archaeology.about.com/od/pterms/g/predorset.htm
The Thule got there around 1200 AD or so.
http://archaeology.about.com/b/2008/08/18/new-dates-on-archaeology-of-thule-migration.htm
But not to Europe.