The illustration below this paragraph illustrates the Bering Strait and connecting bridge as it might have appeared some 21,000 years ago. New genetic evidence suggests that this was the vehicle for the first humans who entered the North American continent. The findings are also a source of debate when countered against the alternative suggestion that the travel route for the first humans to both North and South America involved sea voyages. Evidence now suggests that it was more likely a single migration.
DNA research indicates two definite genetic trends between Siberian and Native American people. One concerns the fact that genetic similarity between the two groups diminishes the further south a native is sampled, and two, that a unique genetic mutation can be found only in Native American and Siberian ancestors.
According to Noah Rosenberg, a genetic researcher at the University of Michigan Medical School:
“We have reasonably clear genetic evidence that the most likely candidate for the source of Native American populations is somewhere in east Asia. If there were a large number of migrations, and most of the source groups didn't have the variant, then we would not see the widespread presence of the mutation in the Americas.”
The techniques used by Rosenberg and his scientific team made it possible to sample DNA from 50 populations, while studying specifically 678 unique genetic markers. Their methods enabled them to gather important information about ancestors long lying on the other side of the sod.
Many questions, however, still remain. For example, once across the bridge, how did these very early settlers travel further southward? (There were no planes to Miami then; not even cheap ones with no frills.)
Time may tell, especially with the help of modern science. It is interesting to consider, however, that native North Americans may all have Siberian ancestry.