Beringia was an ancient landmass that once connected Asia and North America. This region, now largely submerged, allowed for the movement of various species, including early humans, across continents, shaping the distribution of life we observe today.
Understanding Beringia
Beringia was a land bridge connecting northeastern Asia and northwestern North America. Its geographical scope included parts of modern-day Alaska, Siberia, and the submerged land beneath the Bering Strait, extending north to the Chukchi Sea and south to the Bering Sea. At its greatest extent, this landmass reached up to 1,000 km (620 miles) wide, covering an area comparable to British Columbia and Alberta combined, approximately 1.6 million km² (620,000 sq mi).
Beringia formed as a result of global climate shifts during glacial periods of the Ice Age, specifically the Pleistocene Epoch (2.6 million to 11,700 years ago). During these cold periods, large ice sheets accumulated on continents, locking up Earth’s water. This led to a lowering of global sea levels by 120 to 130 meters (400 to 425 feet), exposing shallow seafloors beneath the Bering Strait. The most recent exposure of the Bering Land Bridge occurred between approximately 36,000 and 11,000 years ago, though some debate suggests it may have been present from around 30,000 to 16,000 years ago.
Life in the Beringian Landmass
Beringia’s environment was a distinct “mammoth steppe,” a cold, dry grassland that differed from surrounding glaciated regions. Despite frigid conditions, Beringia was largely unglaciated due to light snowfall, as winds from the Pacific Ocean lost moisture over nearby mountains.
This steppe-tundra landscape supported diverse megafauna. Large herbivores like woolly mammoths, steppe bison, horses, and muskoxen thrived across the expansive grasslands. These animals supported predators such as saber-toothed cats, Beringian cave lions, and gray wolves. Specialized plant life, including dwarf shrubs, provided sustenance for these grazing animals.
Pathways for Human Migration
Beringia served as a corridor for early human migration from Asia into the Americas. The prevailing theory suggests that Paleolithic hunter-gatherers, known as Paleo-Indians, moved across this land bridge from the North Asian Mammoth steppe. This migration may have occurred as early as 30,000 years ago, with populations expanding southward into North and South America no later than 14,000 years ago.
The “Beringian Standstill” hypothesis, also known as the Beringian Incubation Model, proposes that ancestral Native American populations were isolated on the Beringian landmass for an extended period, possibly between 2,400 and 15,000 years, before dispersing into the Americas. Genetic studies, particularly involving mitochondrial DNA, support the genetic isolation of these groups from Asian populations, with a single migration into the Americas hypothesized between 14,000 and 16,000 years ago. While the traditional land bridge route is widely accepted, the coastal migration theory offers an alternative pathway, suggesting early humans may have also moved along the Pacific coast.
The Disappearance of Beringia
The disappearance of the Beringian land bridge resulted from global warming at the end of the last Ice Age. As global temperatures rose around 18,000 years ago, continental glaciers and ice sheets covering large parts of North America and Europe began to melt. This melting released water into the oceans, causing a rise in global sea levels.
Rising sea levels submerged the Beringian land bridge, with the final inundation occurring around 11,000 to 13,000 years ago. Today, the Bering Strait, a body of water connecting the Arctic and Pacific Oceans, marks the location where the land bridge once stood. Remnants of this ancient landmass are still visible as islands within the Bering Strait, including:
The Diomede Islands
The Pribilof Islands (St. Paul and St. George)
St. Lawrence Island
St. Matthew Island
King Island
Ongoing scientific research, including marine archaeology and paleoenvironmental studies, continues to explore these submerged landscapes and surrounding regions to understand Beringia’s past.