What if, for whatever reason, the 53 mile stretch of sea which separates modern Alaska and Siberia were not covered by water? How would the continued existence of a land bridge impact the development of what would become the native cultures of the Americas, and that of future empires in the region such as those of Russia and Britain? Assuming nothing else in the world is changed but for the sea levels in this particular strait, what would the ramifications be on the course of human history? Would there be further waves of migrant folk making their way into the Americas? Would the Amerindians thus prove more resistant to European diseased in any future Columbian Exchange what with land access to Asia? What effects would this have on the ecology of either continent?