How do scientists and historians believe humans came to north and South America?

Scientists and historians believe that the first humans arrived in North and South America via a land bridge known as Beringia, which connected Asia to North America during the last Ice Age, around 15,000 to 20,000 years ago. As the climate warmed and glaciers receded, these early populations migrated southward, gradually spreading throughout the continent. Evidence from archaeological sites, such as tools and remains, supports this migration theory and indicates that these groups adapted to diverse environments over thousands of years. Additionally, some researchers propose that maritime routes may have also played a role in the settlement of coastal areas.