As the earliest secure evidence of Homo is found outside the known region of overlap[4], it is nonetheless possible that H. erectus evolved from H. habilis elsewhere, and that the Turkana basin was a region of secondary contact between the two hominin taxa.
Susan Anton, a New York University anthropologist and co-author of the Leakey work, said she expects anti-evolution proponents to seize on the new research, but said it would be a mistake to try to use the new work to show flaws in evolution theory.
"This is not questioning the idea at all of evolution; it is refining some of the specific points," Anton said. "This is a great example of what science does and religion doesn't do. It's a continous self-testing process."