Final answer:
Fossil and genetic evidence points to Africa as the location where the earliest humans originated. This is further supported by the genetic links between populations within Africa and the rest of the world.
Step-by-step explanation:
The fossil evidence supports the hypothesis that the earliest humans originated from Africa. This is confirmed by substantial genetic research showing that genetic variance in Africa is also found in the rest of the world, suggesting a common African ancestry. Further evidence is provided by archaeological findings, such as the pebble from Makapansgat in South Africa, which demonstrate the presence of hominids in Africa millions of years ago. The out-of-Africa theory is bolstered by human genomes tested outside of Africa having close ties to those in Africa, and genetic variances unique to Africa not present elsewhere.
The idea that modern humans evolved in many places in a piecemeal fashion has been largely discredited in favor of models indicating a single origination point followed by global diaspora. Early humans are believed to have migrated from Africa to other parts of the world, interbreeding with other hominins, like Neanderthals, and adapting to diverse environments, which led to biological diversification. Meanwhile, the Americas were settled much later by humans, which is also supported by valuable archaeological finds across the continent.