That model has been substantially revised in the past twenty years.

Ancient DNA analysis of individuals from across the Americas has revealed a population history far more complex than the simple Clovis-first scenario.

Multiple studies have established that the ancestors of contemporary Native Americans diverged from other Asian populations and entered a period of geographic isolation — possibly in Beringia, the land between Siberia and Alaska that was exposed above sea level during periods of low sea levels — before spreading into the Americas.

During this isolation period, estimated to have lasted thousands of years, the founding population diversified genetically before dispersing southward.