Aug 25, 2012

Settlement of the Western Hemisphere

The theory of human migration from Siberia into the new world via a land bridge has long been the conventional wisdom.  The closest land connection from the old world to the new was between Siberia and Alaska. During the ice age there was a land connection between the two hemispheres since the sea level was lowered by glaciers as shown by the graphic below. The shaded area on the graphic below shows the land above water during the ice age.

This theory has been supported by DNA testing that indicates that most Native Americans are closely related to Asians by MtDNA that is inherited from mother to child, and by Y DNA that is inherited from father to son. The graphic below shows the theoretical movement of people from Asia to the western hemisphere by MtDNA.

The graphic below shows the likely path for the five major MtDNA haplogroups that pass from mother to child.  Haplogroups A, B, C, D follow a similar path from the old world to the new. The only surprise here is that Haplogroup X has few links to Asia, with more to the middle east and Europe.

The graphic below shows the distribution of the "Q" Y DNA passed from father to son. The majority of  Native Americans are descended from "Q" which is also located in Siberia. The two continents are shown to be interconnected by the graphics below.

The theory of a Siberian only connection to the human settlement of the western hemisphere has been challenged by a number of individuals who believe that the Clovis stone age technology is similar to the Solutrean stone age technology found in Spain and France.  "Across Atlantic Ice" by authors Dennis Stanford and Bruce Bradley presents an interesting theory that people could have traveled by boat along the ice pack that connected Europe and the new world during the ice age. They make their stone tools in a very similar manner and in way much different then those made in Asia.  They would have used boating and hunting technologies similar to modern Inuit peoples, hinting seals and fishing and living on the ice.

The graphic below below shows the location of MtDNA Haplogroup X passed from mother to child. Note the concentrations in the northeastern part of North America and Europe, West Asia, and North Africa. There is minimal connection to western Asia and Siberia.

The graphic below shows concentrations of the Male Y DNA R1. Note the concentrations in Europe and central Asia and northeastern north America. 

It appears likely that human migration into the new world was more complex then the conventional wisdom of a connection only from Asia to America on the land bridge. New DNA research will likely improve our understanding. But the last two graphics certainly support a possible connection via the Atlantic Ocean.