QUOTE (Drace @ Mar 25 2014, 03:30 PM)
That's a theorized myth. Part of it comes from the tale of Gilgamesh from what I remember, and not much is really KNOWN about Sumerian culture, it's all more or less theory and conjecture.
As for the gene testing for the eastcoast, there is 5 main genetic sequences they have matched to Native American populations that are seen outside of the Americas. 3/5 come from asiatic cultures an are still shared by most cultures in th artic regions (Eskimo, Inuit, Aluet, Yupik, some Sami etc). 1/5 comes from more southern Asian populations (primarily Korean and Nipponese Japanese) and is primarily located around different areas of the peublo regions especially in New Mexico and is thought to be from Buddhist missionaries (also helps explain why certain languages and cultural/religious rights show signs of early Japanese ones). Te other 1/5 is a genetic sequence found throughout France, south east Europe and in late concentrations near te Gobi desert. This one till hasn't been explained but the main hypothesis is that during the ice age the plates were closer and the populations from a certain region spread out and settles in SE europe, France and NA.
Though the métis connection muddies this a bit as early census never differentiated between Metis or Aboriginal in many areas, and it is quite possible that many natives in those regions carry métis an therefore French genetics from that rather than an late homo migration
If you lower the ocean levels a bit the Continental Shelf becomes dry land. All the continents would be connected. Further, if you look at many of the seas and gulfs, the erosion patterns seem to be backspilled, as if the water levels rose and washed out a lower-lying area.
So, at some point in the past, the ocean levels were lower. All the landmasses were connected and we didn't have many of the seas in Europe and the Gulf of Mexico. As the water levels rose it started cutting off those landmasses (by flooding the Continental Shelf), then backfilled the Gulf of Mexico and other areas, further reducing the ability of living creatures to migrate. Ocean levels are rising every year, which means they used to be lower. Subtract also water levels for more ice formations and whatnot and you get a connected landmass relatively recently (I don't feel like looking up the math for it, but it's there).
Theoretically this explains a lot of things better than (or at least the same as) a Pangaea model. As a plus, you don't need land-bridges or vegetative rafts to bring certain animals across continents. It also helps solve some of the human migratory issues, as they literally just walked away.