Final answer:
The most accepted theories for the first human migration to the western hemisphere are the Bering Land Bridge theory and the coastal migration theory. Both suggest a migration from Asia, via land bridge or coastal routes, around 20,000-14,000 years before the present, supported by archaeological evidence like the Monte Verde site.
Step-by-step explanation:
The suggested ways that people first came to the western hemisphere, which includes North, Central, and South America, are through different migration theories. The primary and well-accepted theories are the Bering Land Bridge theory and the coastal migration theory. The Bering Land Bridge theory suggests that the first humans migrated to the Americas from Asia by crossing the land bridge that connected Siberia and Alaska, following herds of animals. On the other hand, the coastal migration theory suggests that people traveled by sea along the Asian coast and over the Bering Land Bridge, following the marine resources and then down the coast of North America to South America. Sites like Monte Verde in Chile provide archaeological evidence supporting this theory.
A less accepted theory is the Solutrean hypothesis, which suggests that the first humans could have come from the Solutrean culture of Europe. However, there is a lack of genetic evidence to support this theory. The most plausible and accepted explanations for human migration to the Americas are the Bering Land Bridge and coastal migrations, which are believed to have occurred approximately 20,000-14,000 years before the present.