Essentials of Physical Anthropology Study Set 2
Quiz 11 :
The Originand Dispersalof Modern Humans
Today, all the people are categorized as Homo sapiens. The human species first started to evolve about 200000 years ago. It is now evident that early Homo sapiens , or modern humans, were the contemporaries of Neanderthals and did not come after them. Though, it is likely that both Neanderthals and modern humans got to descend from Homo heidelbergenis. In comparison to late archaic humans and the Neanderthals, the modern humans usually possess more delicate skeletons. Their brow ridges usually project much less, and their skulls are more rounded in comparison to pre modern man. They hardly possess the occipital buns, which are found in the Neanderthal skulls back. They also possess comparatively smaller faces, high foreheads, and pointed chins. The first fossils identified of early modern humans were found at 27000-23000 year old Cro-Magnon rock shelter in 1868 in southwestern France. They were afterwards named the Cro-Magnon people. Their musculature and skeletons were less massive in comparison to the Neanderthals. The Cro-Magnon had small, broad faces, high foreheads, and pointed chins. Current information indicates that modern humans got originated from archaic humans mainly in East Africa. In Ethiopia, a 195000 year old fossil from the location Omo 1 indicates the starting of the changes in the skull, which we correlate with the modern people, including a projecting chin, and possibly a rounded skull case.
The Replacement model laid emphasis on the fact that all human beings were evolved in Africa, later they migrated to remaining part of the world. Two types of replacement were given these includes; complete replacement and partial replacement theory. The Partial replacement models given by various paleoanthropologists suggest that the interbreeding occurred mostly outside the Africa. The analysis of DNA conducted by Green and co-workers proved that, the extent of interbreeding was prudent. It also showed that 1-4 % of the modern populations were outside the Africa. On the other hand the population within the Africa had no tinge of the Neandertal genes. Another fact that supports the partial replacement theory is among the modern genera sampled earlier. The sample results revealed that among five humans, three were having some of Neandertal genes. Hence, this theory supports that the interbreeding occurred when humans beings migrated from Africa. Further study conducted revealed, that interbreeding occurred in between the emigrant from Africa and modern human. The remains in the Dennisova cave provide evidences to this theory. Yes, the evidence provided by John Relethford in the partial replacement theory are quite convincing. Since, the results proofed that the DNA of modern man were different from those of in Africa. The alternative method such as genetic patterning of the Africans present within Africa. The genetic patterning studies will provide detailed information of gene flow of Denisovan genes within Asia and in Europe.
Homosapiens (H. sapiens) populations were identified in the area of Africa approximately 200,000 years ago. Their population expanded across the old world within 150,000 years. The various theories given by paleoanthrologists, suggest that H sapiens evolved from Africa and later on emigrated to rest part of the world. The fossils of Homo sapiens recovered from Ethiopia in 2003 were precisely dated and conserved. These fossils were of great importance because it provided detailed information of origin of modern human in that time. It was a combination adult cranium both complete and incomplete along with cranium of child and other cranial pieces. The radiometrically dated fossil is considered to be of best dated. It preserved the Hominin fossils from the period between 160,000 and 154,000 ya (years Ago). It is one of the oldest recovered fossils. Various studies revealed that these fossils were modern to some extent but not completely similar to modern human. The conclusive evidences and facts about the Herto fossil indicated that the modern human evolved from Africa. The fossils of Herto, best matched the genetic data of the replacement model. It provided information that humans evolved from Africa. Later on through interbreeding, they migrated to other parts of the world. Hence, fossils of Herto completely supported the partial replacement theory.