Final answer:
The confirmation that H. erectus evolved in Africa is supported by the fact that earlier hominins originated there and by the widespread fossil evidence and migratory patterns of H. erectus from Africa to other continents.
Step-by-step explanation:
The line of evidence that helps to confirm H. erectus evolved in Africa, aside from all the earlier hominins coming from there, involves the fossil evidence and migratory patterns of this species. H. erectus first appeared approximately 1.8 million years ago, with a belief of origination in East Africa. This species was the first to migrate out of Africa, with fossils found in places such as India, China, and Europe, indicating a significant range of movement and adaptation. H. erectus had several human-like features, such as a larger brain and body size similar to that of modern humans, and lesser sexual dimorphism. Furthermore, the use of fire and tools suggests advanced behaviors that set the stage for later human evolution. Hence, the combination of similar primitive species origins, coupled with fossil distribution outside of Africa, strongly supports the hypothesis of African origins for H. erectus.