Beringia refers to the ancient land and marginal seaway region that connected Asia (Siberia) with North America (Alaska and nearby areas) during periods of lower sea level in the Pleistocene ice ages. It was not a single narrow strip but a broad, periodically exposed belt of dry land and shallow sea areas that allowed flora, fauna, and humans to migrate between the continents. When sea levels dropped, large swaths of the Arctic and subarctic were exposed, forming a land bridge known as the Bering land bridge, which at times extended up to about 1,000 kilometers (roughly 620 miles) wide. This connection facilitated the dispersal of organisms and is widely implicated in the peopling of the Americas, with humans and other species moving from Asia into North America via this route.