Early Humans Outside Of Africa

The oldest early human fossils outside ofAfrica, found in Java (Mojokerto, Sangiran, Figure 6a) and China (Longgupo Cave in Szechuan), are, according to new dating methods, about 1.8 million years old. A similar age has been proposed for the stone tools found at Qrge in southern Spain. The skulls and lower jaws of the hominid finds at Dmanisi in Georgia are only slightly younger (Figure 6b). In northern Israel, though, excavators have unearthed stone tools that are over two million years old. It was thus, at the latest, at this time that the early Homo erectus or a later, not yet archaeologically attested, Homo rudolfensis first left the African continent (see Figure 18). Where their wanderings led them first can only be settled conclusively by future fossil discoveries. At the present it is already clear, nonetheless, that our ancestors left Africa in at least two expansion phases— roughly two million and one million years ago, and at that time they used existing spits of land or the shallow sea level not just to sight a new land but also to settle (see the Appendix, Figure 23). Sardinia, Gibraltar, Greece, and the Near East could all have served as possible bridgeheads for the curious early humans in their emigration to Asia and Europe.

During the first expansion of about two million years ago, the early humans reached southeast Asia, the Near East and Black Sea region, Georgia, southern Spain, and the Levant (see Figure 18). About one million years ago they pushed further and "discovered" central Europe and northern China. In these regions, long cold periods alternated with brief warm spells; climate and living conditions were very different from the African habitat of the first primitive humans. By, at the latest, 500,000 years ago, Homo erectus had settled beyond Africa in east Asia, southeast Asia, and central and southern Europe—despite ice-age climatic fluctuations in some regions. The humans, with their technical and cultural developments, faced new challenges in their new habitats. Thus in the entire Old World the last evolutionary step on the way to modern humans commenced—the transition to "archaic Homo sapiens."

This term is used to describe the transition from the development stage of early humans to that of modern humans. As with the early pre-humans in Africa, "archaic Homo sapiens" existed in various, thus geographical, variants depending on where they settled. The Neanderthals sprang from the European variant of the early human Homo erectus—called Homo heidelbergensis. As the first discovered fossil ancestors, before their recognition as a self-standing human species, they were initially renowned, then misunderstood, and finally recognized in their special position on the human family "bush". For many years, recognition of the development of variants played almost no role in the interpretation of hominid fossils—it was only the age that mattered. Thus the discovery of the first human fossil in Africa, at Kabwe in Zambia, led Arthur Smith Woodward, an expert on fish fossils at the British Museum, to prophesy in 1921 that this skull might give a new lease on life to the idea that the Neanderthal was the true ancestor of Homo sapiens. The skullcap uncovered in Ngandong, Java, between 1931 and 1933 was even classified as a "tropical Neanderthal." Today the classifications of the two finds oscillate between Homo erectus and forerunners of Homo sapiens; a relationship to the Neanderthals is no longer even mentioned as a possibility. For the present understanding of the Neanderthals, this means that the European Neanderthals also constituted only a geographically limited group, contemporary with other geographical variants of "archaic Homo sapiens," which appeared for example in Africa and southeast Asia. As we will see, modern humans, Homo sapiens, apparently finally emerged not in Europe nor in Asia, but in Africa.

At any rate, it is certain that the Neanderthals and the still-existing human species, Homo sapiens, encountered one another in the Near East about 80,000 years ago. In that region they must have lived near and perhaps also with each other for about 50,000 years, until the Neanderthals vanished without a trace about 27,000 years ago. This sudden disappearance naturally raises questions for us modern humans. It is hard to be at ease with the thought that we had another human species as neighbors, even if they died out. The early modern humans who came out of Africa were nonetheless witnesses of both phenomena. Probably the Neanderthals and Homo sapiens were very similar in lifestyle. Both more or less successfully populated inhospitable landscapes, hunted, gathered, developed tool cultures, propagated, and buried the members of their own species. Key to evolutionary success is rate of reproduction. With an estimated population density of roughly 10,000 inhabitants, only two more Neanderthals had to die than were born per year for the species to die out in a surprisingly short time. This is one possible model for understanding the extinction of the Neanderthals. However, it is certain that the Neanderthals' end can by no means be attributed to a more limited intelligence. New studies of ontogenesis, the growth of an individual from egg to adult human, provide evidence that the Neanderthal wasn't such a brute as he used to be regarded. A study has compared the developmental speed of Homo erectus, Neanderthals, and Homo sapiens. The evidence, obtained by study of dental enamel, in which growth rate can be read down to the day, is unmistakable: Homo erectus, the evolutionary sprinter in terms of brain growth and fine motor skills, shows evidence of very rapid growth, while Neanderthals and Homo sapiens grow very slowly in childhood. This means that the offspring of Homo erectus, like chimpanzees, were born with a relatively large brain. Neanderthal babies, however—like those of modern humans—came into the world more "incompetent." Thus, the offspring of Neanderthals and modern humans were and are dependent for a very long time on social assistance and parental care. This finding revolutionized our picture of Neanderthals. They must have lived in fixed social structures, like us, because otherwise they would not have been able to provide the necessary care for their children. Possibly our common roots reach back to the period more than a million years ago, when the Neanderthals' forebears left Africa and our ancestors stayed there a while longer.

The man from the Neander Valley is thus not so alien as was for a long time assumed. The misunderstandings and confusions about the Neanderthal find and the wealth of geographical variety among our ancestors show above all that the science of paleoanthropology, which seeks to solve the puzzle of the human past, is also a historical process. It has undergone change and has been influenced more by subjective factors than by objective ones. No family tree can be regarded as linear or even static. With every new discovery, every newly tested technique for investigating fossils, the window to the early era of humankind opens a crack wider and gives insight into a long-vanished world. For all who are concerned with the fascinating topic of their own origins, this insight is an encouragement always to be open to new ideas and to remain flexible while developing theses and assumptions about early human history. This applies also to research into the Neanderthals, who, with more than 300 individual finds of their fossil species, have been more intensively studied by scholars than any other.

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