Final answer:
The first people likely entered North America during the last ice age, using the Bering Land Bridge between Siberia and Alaska, and possibly also via coastal migration routes along the Pacific shoreline. These theories are supported by genetic links and archaeological evidence, focusing on migration from Asia. The correct answer is options A,B.
Step-by-step explanation:
About 15,000-12,000 years ago, people first entered North America primarily through two routes. The most widely accepted and well-documented routes of migration include:
- Bering Land Bridge migration model, and
- Coastal migration, possibly by boats along the shoreline.
According to the Bering Land Bridge theory, during the last ice age, sea levels dropped, revealing a land connection between Siberia and Alaska called Beringia, which allowed humans to migrate from Asia to the Americas. This theory is substantiated by genetic evidence that shows a link between Asians and Native Americans, and it remains the oldest and most popular theory.
The coastal migration theory suggests that some peoples might have traveled by following the Pacific coastline from Asia, around Beringia, and down to South America. This theory is supported by archaeological findings that indicate settlements predating those of the inland Clovis sites, suggesting a faster spread via maritime routes.
Both theories point towards a migration from Asia, aligning with genetic studies and distances that would make other routes such as crossing from Africa on large ships highly unlikely. The hypothesis involving travel from Europe (Solutrean hypothesis) also lacks substantial evidence when compared to the genetic links found between indigenous peoples across the Americas and populations from Asia. Additionally, no credible evidence suggests that humans crossed glaciers riding on mammoths, which is more of a myth rather than a scientific theory. Thus, the two correct answers are options A and B: 'Coming down the coastline from Asia to South America by boat' and 'Crossing the Bering Land Bridge when a corridor opened through the ice'.