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The First Migration out of Africa
The first Hominid species to migrate out of Africa was Homo erectus. The site of Ubeidiya in Israel contains Homo erectus remains dating to 1.7 million years ago. In Georgia there are also remains of a sub-species of Homo erectus, known as Homo erectus georgicus, dating to 1.8 million years ago. (See map 1: 1.7 million years ago) From the remains of Mojokerto Child, we know that by 1.4 million years ago Homo erectus had migrated all the way across Asia to reach Java (which at the time was connected to the mainland by a land bridge. (See map 2: 1.4 million years ago).
By 800,000 years ago, Homo erectus had reached Western Europe, Northwest Africa, and China, and had already begun to evolve and adapt to the different environments it found. It was gradually developing a larger brain that allowed it to make more complex tools. Palaeontologists refer to the larger brained, more human like Homo erectus specimens as Homo heidelbergensis. But because the transitional fossils between these two species are gradual and different in different parts of the world, it is not always clear into which species individual specimens belong. The picture is further complicated by specimens that were found in Western Europe during this period that some palaeontologists consider as another distinct species: Homo antecessor. (See map 3: 800,000 years ago)
Between 500,000-250,000 years ago, we see the descendants of Homo erectus / Homo heidelbergensis really start to diverge into truly separate species in the different regions of the world. The hominids in Europe start to evolve into what will become the Neanderthals, whilst in Africa we see Homo heidelbergensis specimens with very large brains that will eventually evolve into modern man, for example the Bodo Cranium, discovered in Ethiopia and dated to 600,000 years ago, already had a brain size of 1,250 cc (Conroy)(about 88% of the size of modern man). In East Asia, Homo erectus was also developing larger brains, but at a slower rate. The finds refered to as “Peking Man” and those uncovered at Yunxian have an average brain size of about 1,075 cc.
By about 130,000 years ago, we can see 3 clearly different hominid species have evolved. The Neanderthals, a hominid species very similar to modern man, but stronger, stockier, and more adapted to cold environments, lived in Europe and the Middle East. In East Asia, smaller brained Homo erectus hominids were still thriving. And in Africa Homo sapiens (modern man) had evolved. (See map 6: 130,000 years ago) All 3 of these species had originally developed from Homo erectus and all three had evolved larger brains as a survival strategy. But only one of them would have what it took to dominate the world and outcompete the other two: Homo sapiens.
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