Out of Africa is about the recent African origin of modern humans. Since the 1980s this has been supported by a study of present-day mitochondrial DNA, and other sequence analysis. There is also evidence based on the physical anthropology of archaic fossil remains. The idea is very well supported. There are differing theories on whether there was a single exodus or several. A growing number of researchers also suspect that "long-neglected North Africa" was the original home of the modern humans who first trekked out of the continent.