Final answer:
The origins of modern humans are explained by three models: the 'out of Africa' model, the 'multiregional evolution' model, and a third that suggests interbreeding between early humans from Africa with other species during their migration.
Step-by-step explanation:
The question refers to the three models discussed in class for the origins of modern humans. The first is the "out of Africa" model, which suggests that modern humans first emerged in Africa around 200,000 years ago, and then spread out of Africa replacing other human species approximately 100,000 years ago. The second model is the "multiregional evolution model", indicating that Homo sapiens evolved from Homo erectus in various regions concurrently. The third model, not explicitly mentioned in the initial information but suggested by recent genetic evidence, involves interbreeding between early humans from Africa and other hominin species as they spread across the globe.
These theories are not necessarily exclusive of one another. Advances in archaeology and molecular genetics, such as studies of mitochondrial DNA and the Y chromosome, offer growing complexity to these models and suggest a more intricate picture of human ancestry that may incorporate elements of both models. While the "out of Africa" and "multiregional evolution" theories are the most taught, the emerging evidence proposes a more blended scenario, with modern humans or their ancestors emerging in Africa before mixing with other human species around the world.