Final answer:
Scientists believe that hominins in the Homo sapiens group migrated to North and South America through the Bering Land Bridge and coastal migration theories.
Step-by-step explanation:
Scientists believe that hominins in the Homo sapiens group migrated to North and South America through two main theories: the Bering Land Bridge and the coastal migration. The Bering Land Bridge theory suggests that early humans crossed a land bridge that connected eastern Russia to Alaska during an ice age, around 12,000 years ago. The coastal migration theory suggests that early humans traveled along the coast of Asia, using boats or canoes to reach the Americas. Both theories are supported by evidence and genetic studies.