What is the term used to describe the theory that modern humans evolved in Africa and migrated to other parts of the world?

The term "Out of Africa" refers to the widely supported theory that anatomically modern humans (Homo sapiens) originated in Africa and then migrated to other regions of the world. This theory is significant because it suggests a single origin of modern humans, indicating that they share a common ancestry in Africa before spreading out globally.

The evidence supporting the Out of Africa model includes genetic studies that show the majority of human genetic diversity is found within Africa, while populations that migrated out show relatively less diversity, pointing to a recent common lineage. Additionally, fossil records indicate that early Homo sapiens appeared in Africa around 200,000 to 300,000 years ago before subsequently dispersing to other continents.

In contrast, other theories like the multiregional theory propose that modern humans evolved simultaneously in different regions of the world, arguing for a more complex interaction between archaic and modern human populations. Adaptive radiation refers to the process by which organisms diversify rapidly in response to new environmental challenges or opportunities, while regional continuity suggests that there was a continuous evolution of human populations in various regions. These concepts differ fundamentally from the Out of Africa model, which emphasizes a singular origin and subsequent migration.