The species here are listed roughly in order of appearance in the fossil record (note that this ordering is not meant to represent an evolutionary sequence), except that the robust australopithecines are kept together. Ardipithecus ramidus It is the oldest known hominid species, found in the Middle Awash region of Ethiopia in 1994 by Tim White and dated at 4.4 million years. Most remains are skull fragments. Indirect evidence suggests that it was possibly bipedal, and that some individuals were about 122 cm (4'0") tall. 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.
Origins of Early Hominins Humans know or understand the theory of evolution and how they evolved from apes, but there is always talk of a missing link between apes and modern humans. Apes did not just suddenly evolve into modern day humans. Apes evolved into another species that fall into the relation of modern humans. This is what the missing link is referring to; we call the species hominins. Hominins comprised of many species actually, including but not limited to, Australopithecus afarensis and Homo erectus.
These proto-humans roamed the savannahs and Rift Valley of Africa more than 3 million years ago, and are closer to modern humans than apes. However, new evidence suggests that the Australopithecus family was not the only hominid species to have existed at this time. 'Nature' describes a new species - Kenanthropus platyops - with a much flatter face than any Australopithecine. "Kenyanthropus shows persuasively that at least two lineages existed as far back as 3.5m years," said Meave Leakey of the Kenya national museum. It is clear that the evolutionary tree is far bushier that at first appeared.
4. The word hominid refers to members of the family of humans. It includes all species from our human ancestors and also all living apes, such as the Hominoidea. The hominid fossil record will not be complete for a long while, but there is enough evidence for researchers to give us good idea about the history of humans. There are a number of fossils that have been found throughout the researchers journeys.
The fossil was a lower left humerous dated to be about 4.0 million years old. Australopithecus afarensis This species existed between 3.9 and 3.0 million years ago. It had an apelike face with a low forehead, a bony ridge over the eyes, a flat nose, and no chin. They had protruding jaws with large teeth. The skull is similar to that of a chimpanzee except for more human like teeth.
The origin of modern humans is one of the most widely debated concerns in the area of paleoanthropology. Ever since the discovery of the Neanderthal in the mid 1800’s, scientists such as Charles Darwin and many others have been overly curious about the similarity of man to certain great apes and how over long periods of time have evolved from different archaic forms of humans up to today’s homo sapiens. There are two major theories that encompass how modern humans may have evolved from the various groups of hominids that existed in the Old World. These two theories are the Multiregional origin theory and the “Out of Africa” origin theory. I will first introduce the background and logic behind the two theories, and then I will argue, with supporting genetic evidence, why the “Out of Africa” theory is currently the most widely accepted in the field.
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. 2007). This species was also known as “Handy man” or “able man”. Homo habilis had a smaller brain of about 630 C.C. compared to living humans today (Relethford, 2010).
The lack of cranial fossils for 2 million years is a problem. We do not know what took place during this time. The first available cranial fossils are those of A. afarensis. The mean endo cranial capacity was 413.5 cm3, which means that its brain size was that of today’s African great apes (Changeux and Chavaillon pg. 65, table 4.1).
The Austalopithicus was found in African and was know to have lived from 4.2 to around 1.0 million years ago (Standford 251). They had a small body like an ape that would get approximately 64 to around 100 pounds. They had a big jaw with a U-shaped mouth of small teeth. The brain size of a Australopithicus was small and would get approximately 340 to 500 cc, which is in the same range as gorillas and chimpanzees brain sizes. The top of their skull was of a bony ridge.
Are we still evolving? How do humans and apes share a common ancestor? Modern human species or Homo sapiens have shown great similarities in the physical and genetic makeup to another group primates species, the apes. Both organisms share a common ancestor dating back eight to six million years ago. Evolution means change over time.