Ancient America

25 Jul 2010

The Guardian July 24th .... a study of the remains of a woman who lived on Mexico's Caribbean coast in the early Holocene period is causing a change of attitude among prehistorians. Anthropologists were sure humans initially migrated to the Americas in a short window of time after the end of the Ice Age and came from a limited region in NE Asia. The reconstruction of the woman's face and body have thrown this idea up in the air as she resembles in many details a person akin to modern people in SE Asia - particularly, Indonesia. Hence, the Americas were populated not necessarily by waves of people from across the Bering Strait but by a direct trans-Pacific route as well. Even with the evidence staring up from the woman's face the old school are resistant, saying that genetic evidence supports an ancestry in NE Asia. The old idea of big game hunters chasing mammoths across the Bering land bridge won't go to bed. Many other things depend on it, such as an explanation for the mammoth extinctions.

It should not really be too much of a surprise that Indonesians reached the Americas at a fairly early stage in the Holocene. During the last glacial period Indonesia was a much larger block of land. What is now the Sunda continental platform, joined Malaysia, Sumatra, Java and Borneo into one large feature covered in tropical forest. At the same time New Guinea was joined to Australia by the Sahul continental platform and a deep channel of water that exists between Sunda and Sahul is thought to have kept the two regions apart, which is self evident by the peoples that inhabit the two regions - differing from each other in fundamental respects. The situation in the early to mid Holocene appears to be that these platforms remained above sea level but were low lying areas that were probably swampy with a lot of coastal vegetation and tropical forest on higher points. Now, if you accept the idea that sea levels rose exponentially as a result of melting ice sheets and glaciers the drowing of the Sunda and Sahul would have been a fairly slow process, but if you tend to think in terms of something more dramatic and then they would have disappeared around 8000 years ago as a result of a changing geoid. Whether the drowning was slow or rapid there is no reason to think people were not able to move across the Pacific - after all the Polynesians spread that way just a few thousand years ago.