Multiregional origin of modern humans

As a hypothesis of the multiregional origin of modern humans ( also: multi-regional model ) is called in paleoanthropology the assumption that the " for today's large groups of people - such as the Asians, the indigenous people of Australia or the Europeans - characteristic features emerged in a long period have, and that this was also about where these people live " the proponents of this hypothesis on the phylogeny of the people close so " dramatic migration and displacement scenarios and take demic diffusion [ ie. thorough mixing of the gene pool of diverse populations due to continuous gene flow ] with at selection. "

The hypothesis of the multiregional origin of modern humans is the opposite to the out-of -Africa theory that Homo sapiens evolved in Africa from precursor species, 50,000 to 60,000 years ago came to the Middle East to Asia, Australia and later to Europe and which there already resident populations of the genus Homo displaced.

The multiregional hypothesis has also been invoked to explain the emergence of human races and is " by a small group of passionate advocates " - represented - particularly from China. Detailed genetic analyzes of Asian ethnic groups occupy but also for this region an influx of Homo sapiens from regions west of India.

Historical Background

The term Homo sapiens as a species name for humans in 1758 by Carolus Linnaeus in the tenth edition of his Systema Naturae Scripture (p. 20) introduced; Linnaeus had previously asked the people without epithet to the genus Homo, but in addition ( albese europaeus, americanus rubese, asiaticus fuscus, Africanus nigr. ), four regional, on the basis of skin color distinguishable variants named. As in all previous editions, Linne waived but continue on the so-called diagnosis, ie a concise description of the species-specific features.

In the following decades, although various lists of species-typical features were created. Also put the botanist William Thomas Stearn 1959 subsequently a particular individual as a scientific specimen copy fixed by declaring Carl Linnaeus ( " Linnaeus himself" ) for lectotype of the species Homo sapiens; since Linnaeus is buried in the cathedral of Uppsala, his remains, however, are inaccessible. Although the feature catalogs wore basically help to distinguish man from other animals alive today; but they proved to be of little help to assign the currently known hominin fossils of the species Homo sapiens or distinguish them from her. In Yearbook of Physical Anthropology 2010 it was said: "Our species Homo sapiens has never been the subject of a formal morphological definition that would help us to recognize our own kind in any useful way in the fossil record. "

The absence of a generally accepted description of the species-specific characteristics of the people had an impact on anthropology in the 19th century. In fact, Dutch physician and naturalist Philippe -Charles Schmerling 1833 described in his book Recherches sur les ossements fossil découvertes dans les cavernes de la province de Liège two fossil skulls ( Engis 1 and Engis 2) and several other bones from a cave at Engis, the he then assigned based on animal fossils and stone tools also discovered the " Pleistocene " (Pleistocene ). With reference to the Genesis, from such a high age could not be determined, and lack of sufficiently accurate demarcation criteria of this first scientifically described Neanderthal, however, was mistaken for a "modern". This did not change in 1863 and the accurate assessment of the geologist Charles Lyell nothing there - also in 1863 - discovered even the influential supporters of Darwin's theory of evolution, Thomas Henry Huxley, the discovery of Engis as a " man of low degree of civilization " coming and the 1856 Fund from the Neandertal - like others before him - described as lying within the range of variation of the now - people. As Huxley arranged other anthropologists of the late 19th and early 20th century, the increasingly more numerous hominin fossils human "races" as their representatives early on, for example, the findings from Balzi Rossi. At the same time repeated conjectures have been published on a polyphyletic origin of these "races" and, for example, the Malays and the Orang -utans attributed to a closer phylogenetic proximity and the African apes and the other "races" of Homo sapiens.

The existence of precursor species of the species Homo sapiens was indeed finally recognized at the latest in 1950 with Ernst Mayr's lecture on " Taxonomic categories in fossil hominids " during a Cold Spring Harbor Symposium of the professional world, but also Mayr had appointed no criteria for the delimitation of species. How could those of Franz Weidenreich in 1947 represented statement, Asian hominin fossils were the remains of ancestors of today's Asians and Neanderthal fossils were the remains of the ancestors of today's Europeans persist. Tapered was this interpretation of the fossils in 1962 in the racial theories of the U.S. anthropologist Carleton S. Coon, who likewise looked at Africa as the most likely place of origin of Homo sapiens. However, this Africa had left on a very primitive stage of development and is split into five evolutionary lines. From these lines (, capoid '= South African Bushmen, negroid ', ' caucasoid ', ' mongoloid ', ' Australoid ' ) be the "races" of anatomically modern humans emerged, and some races the stage of development of Homo sapiens had reached earlier than other.

The basic assumptions

Today's version of the hypothesis of the multiregional origin of modern humans in the mid- 1980s by the U.S. anthropologist Milford H. Wolpoff ( University of Michigan ) and the Chinese paleoanthropologists Wu xinzhi (Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences) formulated as an explanation scheme for the course of recent human evolution.

One of the basic assumptions for this hypothesis, with his Australian co-author Alan G. Thorne in 1992 and then again in 2003 published Milford H. Wolpoff in English and German, on the assumption that the out-of -Africa theory is implausible: "We have. difficulties with the assertion that a single group of hunter-gatherers all other groups of people in a very short time the world - beginning about 200,000 years ago - had completely replaced " a second basic assumption was derived from an observation in the present and reads:" Today's populations retain their physical features in spite of migration and mixing. So it was always, as long as man Europe and Asia inhabited ", specifically, since " people from at least a million years, first left Africa. " In light of these assumptions, it is possible to explain why the Homo populations in Africa, Asia, Australia and Europe on the one hand over hundreds of thousands of years lived apart from each other and were able to develop different physical characteristics, " which have survived to the present time ", although " such a strong gene flow between the groups instead of [ found ] that the people only as a type consist remained. "In 2000 explained Wolpoff et al., that this gene flow between the continents of already " could be maintained a few people a generation ", possibly even from a single zugewandertem individual per generation.

Starting from these basic assumptions of the genus Homo attributed fossils are interpreted by the representatives of the hypothesis of a multiregional origin of modern humans. To this end, published Wolpoff, Wu, and Thorne 1984, a longer list of morphological characters for the previous and the present-day man in the territory of China are typical in particular. " This compilation is based largely on descriptions of Frankfurt anthropologist Franz Weidenreich, who had in China analyzed during the 1930s and early 1940s, the remains of Peking man. " In the result, neither for East Asia ( fossil Homo: Peking Man ) are still for Indonesia ( fossil Homo: Java Man ) anatomical " evidence [ found] that in these regions ever characteristic of Africa Features have replaced the formerly typical there. " Even the Zhirendong - finds have been interpreted in this way.

The same continuity - a gradual transition from Homo erectus to Homo sapiens, largely independently in several regions - was derived in 1992 and again in 2003 by Thorne and Wolpoff also in Europe discovered fossils. To demonstrate this, for instance, could the 70,000 -year-old, late Neanderthal from La Ferrassie apply, which - in contrast to older Neanderthals - " a slight chin projection " has, a feature which is considered typical of the early Homo sapiens. The shape of this feature is interpreted by other researchers in terms of parallel evolution, as developed independently from each. Thorne and Wolpoff suspect, however, "that the Neanderthals either self-developed in a subsequent human forms or mingled with those that perhaps both. " This thesis was, for example, in 2001, by comparing a 13,000 and 15,000 year old skull ( Willandra Lakes Hominid 50 attempts to undermine = WLH 50 ) in New South Wales (Australia ), which is without a doubt Homo sapiens, with supposedly hybrid Cro-Magnon/Neandertaler-Schädeln from Mladeč (Czech Republic) and Homo erectus finds from Java. The anatomical similarities described by the authors were cited as evidence that a replacement of the original homo- populations by immigrant Homo sapiens individuals " can be excluded. " Goal of argumentation is to " recognize the Neanderthals as ancestors ." There have been assigned to the human remains from Mladeč reference to the teeth, however, clearly Homo sapiens and dated between 31-27000 BP, there is a considerable time gap to secured dated late Neanderthals. Also in the hybrids discussion that ensued around the 1998 found Gravettian grave Lagar Velho from to putative Neanderthal features not limited to clear-cut anatomical parameters. Similar objections exist against the hypothesis of some Israeli scientists that Homo erectus had been replaced by a new hominin species in the territory of present-day Palestine 400,000 years ago, from the " emerged later [ Homo sapiens ] populations in the Levant. "

The 1987 mitochondrial under the heading Eva became known studies of human mitochondrial DNA, which are considered methodologically independent support of the initially derived only from fossils Out - of-Africa theory, be recalling allegedly questionable assumptions at run speed of the molecular clock ( " one in each case, worthless clock " ) discarded.

Criticism

Richard Leakey had already in 1994 discussed the pros and cons for the multiregional hypothesis and acknowledged going to have entertained for a while sympathy for this hypothesis. His conclusion was, however: it was " unlikely that they zutreffe ". His skepticism justified Leakey with several arguments, which also - are still carried forward by other scientists - almost 20 years later.

Firstly Leakey pointed to a series of fossil discoveries from several caves in Israel ( Qafzeh and Skhul ); there had been found the remains of Homo sapiens, who were older than adjacent remains of Neandertals. The Neanderthals were so - unlike previously derived from the chronological sequence of dated Neanderthal and now - people - finds - not the direct ancestors of Homo sapiens. Thus, " one of the most compelling pillars to support the hypothesis of a multiregional evolution" was broken. Furthermore Leakey argued with reference to the 90,000 -year-old finds of Homo sapiens from Skhul ". No human fossil this age was found somewhere in the rest of Asia or Europe," More, of the anatomical features of the fossils were completely independent arguments for the Leakey distinguishable tooling production of Homo sapiens and the other resulting from Homo erectus populations and - thirdly - the well-known since 1987 genetic findings on the so-called mitochondrial Eve.

Much had already Chris Stringer and Peter Andrews argues that the first time in 1988 had set in a publication previously published in genetic findings in relation to fossil traditions. For Europe and Asia, they referred in this study among others the lack of transitional forms between Neanderthals and now - people, although there are numerous types of both homo- fossil evidence. You mentioned the evidence of Homo sapiens in the Levant before the year tens of thousands (probably immigrated from the north ) Neanderthals. The fossils from Asia - and especially China - alleged a gradual transition from Homo erectus to Homo sapiens, they finally suggested as an interpretation of less relevant features (of Homoplasien ) due to the total absence of evidence from this crucial period of 100000-50000 years ago According to a study by Chinese experts and according to Peter Brown, there are between 125000-104000 year old Xujiayao fossils and either 10,000 or maximum 24000-29000 year-old Upper Cave skulls not a single reference of hominin bones in China, where discoveries could be reliably dated.

Up to the present the three main arguments against the hypothesis of a multiregional origin of modern humans (lack of Neanderthal / now - people - continuity; genetic testing; misinterpretation of transitional forms in Asia) rejected by their followers. So Milford Wolpoff reaffirmed in 2004 its interpretation of the Neanderthal finds in an emphatic overridden publication ( " Why not the Neandertals? " ), Wu xinzhi presented in 2009 a further lower jaw, its age estimated at around 100,000 years ago and was an early homo sapiens attributed, and the genetic findings will continue to be unusable because unreliable classified.

In contrast are various studies that the 1984 published catalog of allegedly typical morphological features of today's Chinese people -. Was tried by which to prove the continuity of Homo erectus to Homo sapiens - compared with the characteristics of people from other regions Their findings summarized the German paleoanthropologist Günter Bräuer, who in the late 1970s analyzes the African finds and their date and shall, together with the South Africans Peter Beaumont as the founder of Out - of-Africa theory, thus:

The " majority of the population geneticist " therefore supports today as in the mid- 1990s, " most plausible biologically on. " Out- of-Africa theory as