Final answer:
DNA evidence supports the theory that Homo sapiens originated in Africa and later migrated out to populate other parts of the globe. They interbred with Neanderthals in Europe and Asia before eventually populating the Americas starting around eighteen thousand years ago.
Step-by-step explanation:
Studies on DNA indicate that Homo sapiens originated in Africa. This is supported by the genetic evidence showing that all human genomes tested outside of Africa are closely related to genomes of people in Africa. Moreover, there is a greater genetic variance found within African populations than in those elsewhere in the world. This suggests that modern humans arose in Africa from Homo erectus and migrated out of Africa about 100,000 years ago, in a second major migration wave, and that they interbred with Neanderthals who were present in Europe and Asia. Ancestral humans like Homo erectus migrated out of Africa nearly two million years ago, traveling to parts of Asia, the Near East, and Europe. However, they did not reach the Americas during this migration. The population of the Americas began with the arrival of Homo sapiens, starting around eighteen thousand years ago, leading to the rich and diverse cultures found there today.