According to Microsoft Encarta Encyclopedia ’98, between about 2.5 million and 3 million years ago, A. afarensis clearly evolved into A. africanus. A. africanus had a brain similar to that of its ancestor. However, although the size of the
They argue that early modern humans show some traits consistent with a ... ... middle of paper ... ...iation in modern human populations suggests that our origins may reflect a relatively small founding population for Homo sapiens. Analysis of mtDNA (Rogers and Harpending 1992) supports the view that a small population of Homo sapiens, numbering perhaps only 10,000 to 50,000 people, left Africa somewhere between 50,000 and 100,000 years ago. There is another similarity between human populations standing in strong contrast to the condition seen in our closest living relatives, the chimpanzees. In fact, there is significantly more genetic variation between two individual chimpanzees drawn from the same population than there is between two humans drawn randomly from a single population. Furthermore, genetic variation between populations of chimpanzees is enormously greater than differences between European, Asian and African human populations (Cavalli-Sforza, 2000).
This find could be the beginning of many which could completely change our current ideas of human evolution. This pushes back the dates of human history by 2 million years. If Toumai is truly a common ancestor of humans and chimpanzees this makes the molecular clock theory wrong. The molecular clock dates the divergence of humans and chimpanzees somewhere around 5 million years ago while the Toumai discovery suggests that is was 6 to 7 million years ago. (Bower 2002) Homini... ... middle of paper ... ...of the same kind.
The Human Brain Through the use of molecular biology it is thought that the hominidae family first appeared about 5 million years ago. Based on this time frame it is believed that an African Hominoid lineage was present shortly before that time, approximately 10 myp, which contained the common ancestor to both the chimpanzee and human. The split into proto-chimpanzee and proto-human occurred during the last million years of the Miocene epoch. (Changeux and Chavaillon pg. 61).
Hominins comprised of many species actually, including but not limited to, Australopithecus afarensis and Homo erectus. Homo erectus may have been a direct descendant of modern Homo sapiens. These species hold strong evidence that they are the missing link between apes and modern humans. There are many pieces of evidence that lay the path of evolution from these species to modern humans, “…these include anatomy, living primate behavior, and genetic relationships” (Stanford, 237). Australopithecus afarensis comes first, existing about 3.9 to 2.9 million years ago, with intermediate anatomical traits between living apes and modern humans; their fossils were found in Africa (Yukimoto).
From 1967-77 he and his co-workers dug up around 400 fossils, that accounted for 230 individuals. The most important discovery was an almost complete skull found in 1977, which Richard believe to be a new species called Homo habilis. Richard Leakey’s accomplishments are discovering the crania of Australopithecus boisei in 1969 with the archaeologist Glynn Isaac on the East shores of Lake Turkana, Homo habilis in 1972, and Homo erectus in1975. He was appointed administrative director in 1968 of the National Museum of Kenya, and in director 1974. Since 1989 he has been director of the Wildlife and Conservation Management Service, Kenya.
This cave has produced a 2 million year old mandible fragments with features supporting both ideas of origins from the Chinese and West, not yielding to a single, simple explanation. As to where these apes made their signature development onto the open, flat land is debated indefinitely. Approximately 1.7 million years ago, Homo erectus arose in Africa and shortly thereafter spread to other continents, as most scientists believe. As they expanded their range and increased in population, H. erectus may have exterminated H. habilis. Then transition from H. erectus to H. sapiens occurred about 400,000 years ago, and the dispute is over the place of origin of modern humans.
According to Relethford, Hominin is a tribe that comprises of humans and their closest ancestor. Hominin family has shown some resemblances with the evidences collected from fossil records as well as the evolutionary processes to the mordern humans. This article will try to describe the evolution of homonin tribe from the time period of Homo habilis to Mordern Homo sapiens. It will emphasis on the cranial capacity “skull proportions”, tools used and the cultural behavior. Homo habilis species was first found in East Africa at the Olduvai George site, approximately 1.9- 1.4 million years ago (Spoor et al.
The teeth are intermediate between those of earlier apes and A. afarensis, but one baby tooth is very primitive, resembling a chimpanzee tooth more than any other known hominid tooth. Other fossils found with ramidus indicate that it may have been a forest dweller. This may cause modification of current theories about why hominids became bipedal, which often link bipedalism with a move to a savannah environment. Australopithecus anamensis This species was found in 1994 by Maeve Leakey in Kanapoi and Allia Bay situated in North Kenya. The material consists of 9 fossils, mostly found in 1994, from Kanapoi, and 12 fossils, mostly teeth found in 1988, from Allia Bay.
Anamensis is thought to have existed between 4.2 and 3.9 million years ago. The teeth and jaws are very similar to those of older fossil apes. A partial tibia supports bipedality. The first fossil of this species was found in Kanapoi Kenya by Bryan Patterson. The fossil was a lower left humerous dated to be about 4.0 million years old.