When did the initial peopling of the Americas begin according to long chronology theories?
The initial peopling of the Americas began as early as 40,000 years ago according to long chronology theories. Genetic evidence indicates a founding population experienced a standstill of approximately 20,000 years before spreading across the New World. The haplogroup most commonly associated with Indigenous Amerindian genetics is Y-chromosome haplogroup Q1a3a, which has been present in South America for at least 18,000 years.