What evidence supports the Out of Africa hypothesis regarding human ancestry?

The Out of Africa hypothesis suggests that modern humans (Homo sapiens) originated in Africa and then migrated to other parts of the world, replacing earlier hominin species. One of the key pieces of evidence supporting this hypothesis is mitochondrial DNA (mtDNA) analysis, which traces back to a common ancestor.

Mitochondrial DNA is inherited maternally, meaning it is passed down from mothers to their offspring. By analyzing variations in mtDNA from populations around the world, scientists can trace genetic lineages and determine how populations have diverged over time. The results show that all non-African populations have a common ancestral lineage that can be traced back to Africa, indicating that the most recent common ancestors of all living humans lived in Africa. This genetic evidence aligns with the archaeological and fossil evidence supporting the idea that modern humans originated in Africa before dispersing globally.

This mtDNA evidence is significant because it underscores the relatively recent emergence of Homo sapiens as a distinct species and their subsequent migration patterns, which effectively aligns with the timeline proposed by the Out of Africa hypothesis.