| Multiregional Hypothesis |
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.]] The multiregional origin hypothesis of human species holds that some, or all, of the genetic variation between the contemporary human Race s is attributable to genetic inheritance from either '' Homo Sapiens '' Subspecies , or even other hominid species, that were dispersed geographically throughout Asia , and possibly Europe and Australasia , prior to the evolution of modern '' Homo Sapiens sapiens'' (conventionally dated to at least 70,000, possibly 150,000, years ago). The contributing populations suggested by multi-regional hypothesis as sources for additional genetic variation in modern ''Homo sapiens'' include '' Homo Neanderthalensis '' and Peking Man (a local subspecies of '' Homo Erectus ''). This view contrasts with the Single Origin Hypothesis , which holds that modern ''Homo sapiens'' evolved from a single, geographically localised, ancestral hominid population, whose descendants ultimately replaced all other species of hominids over the course of tens of thousands of years without interbreeding or subspeciation. RECENT EVIDENCE The multi-regional hypothesis was originally developed from the Fossil evidence, but more recent work has focused on Molecular data, in which DNA is Sequenced . In particular, work has been done with non- Recombining DNA such as Mitochondrial DNA and the Y Chromosome . In , the US , and the UK examined the Y-chromosomes of more than 12,000 people from across Asia and found no traces of any ancient non-African influence. {Link without Title} . This is of no surprise, because current understanding is that the earlier hominid species have originated also from Africa. Nevertheless, proponents of multiregionalism such as Wolpoff believe the molecular data can not only be reconciled with the multiregional origin hypothesis but in fact in some cases supports it. For instance, studies on past Population Bottleneck s that can be inferred from molecular data have led them to conclude that the single-origin hypothesis is untenable. Discovery of a possible hybrid ''Homo sapiens X neanderthalensis'' fossil child at the Abrigo Do Lagar Velho rock-shelter site in Portugal in 1999 raised hopes of rehabilitating the Multiregional hypothesis. Recent, non-fossilized discovery of one metre tall, small brained (350 Cc ), '' Homo Floresiensis '', on Indonesian island of Flores , imply populations of '' Homo Erectus '' survived very late, and gave rise to even later, physically smaller "Erectus" type isolated groups. The existence of '' Homo Neanderthalensis '', Late full sized '' Homo Erectus '', and now '' Homo Floresiensis '' as contemporaries of modern '' Homo Sapiens Sapiens '' tends to refute the "serial development theory" on its face, and imply something of a more "parallel" development scenario. PROPONENTS OF MULTIREGIONALISM Two of the scientists most closely associated with the multiregional hypothesis are Carleton S. Coon and Milford H. Wolpoff . Wolpoff, however, distinguishes his own views from Coon's as follows: : "Since its inception in the 1980s, multiregional evolution has never been polyphyletic. It has always been a theory about intraspecific evolutionary processes with an emphasis on gene flow... multiregional evolution not a polyphyletic model of parallel racial evolution similar to that of Carleton Coon’s in the 1960s." [http://human-nature.com/nibbs/02/wolpoff.html] However, Coon was explicit in the exposition of his theory that Gene Flow between populations played a substantial role in human Evolution , a point often overlooked by his critics. A variation of this theory known as Hybrid-origin hypothesis was introduced in 1971 by the British psychologist Stan Gooch . A recent Australian study of an ancient Aboriginal skeleton known as Mungo Man could be interpreted to support the multiregionalism hypothesis. The reasons for this is that genetic tests show the DNA of Mungo Man to be unrelated to those of modern man on the Mitichodrial line. Mungo man is an anatomically modern human and has been dated to be at least 40,000 years old. The study suggests that Mungo Man must have had a different direct ancestor on the female line to modern humans a branch that is now extinct. This tends to support the hybrid origin hypothesis. PRE-MODERN (NON-''SAPIENS'') HOMINIDS Because of the scarcity of Fossil s and the discovery of important new finds every few years, researchers disagree about the details and sometimes even basic elements of Human Evolutionary History . While they have revised this history several times over the last decades, researchers currently agree that the oldest named Species of the genus '' Homo '', '' Homo Habilis '', evolved in Africa around two million years ago, and that members of the genus migrated "out of Africa" somewhat later. The descendants of these ancient migrants, which probably included '' Homo Erectus '', have become known through fossils uncovered far from Africa, such as those of " Peking Man " and " Java Man ". The '' Homo Neanderthalensis '' is also considered a descendant of early migrants. Source: Single Origin Hypothesis SEE ALSO EXTERNAL LINKS
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