Final questions Essay Example | Topics and Well Written Essays - 1000 words

Final questions - Essay Example This space was small and at the rear of the skull in quadrapedal animals. It moved a little forward and grew to about 6 times the earlier one for knuckle walkers, like gorillas. For bipedal animals it moved even further forward and nearly doubles in size. This makes sense, as the place where the spinal column enters the skull would govern the angle at which the head is carried (Howells 77-205). Lucy from Oldivai Gorge in South Africa is the most complete skeleton of this genus, which walked upright and may have used very simple tools. It probably lived in trees, but hunted or scavenged on the ground, as the curvature of fingers and toes indicates it could climb trees. The pelvis in the female is the same as modern man. The long forehead slopes at about 45 degrees from the bony ridge over the eyes, and there is no real chin. Two sets of footprints preserved by volcanic action and found by Mary Leakey show human toes, and they prove that Australopithecus Afarensis walked on two feet ha bitually, though the placement of feet show a more splayed gait and suggests that this ape was not quite upright ("Early Human Evolution: Early Transitional Humans."). One of the difficulties with the fossil records is that there is no way of knowing how many species exhibiting changes came between one recovered fossil and the next. This is why there is disagreement about exactly where the branches might be. Without DNA evidence it is not possible to know for sure which hominid is the ancestor of which others. Even with DNA evidence it would not be certain, as it would requires some from all the fossils in the line. Australopithecus Africanus followed next. However, it is not certain where homo branched off. It could have been from Aferensis, Africanus, Robustus or even a separate Paranthropus Robustus. All of these were inhabiting the same area as contemporaries. There might even have been interbreeding, which would indicate that the breeds were not really separate. The Robustus de finitely had larger bones and brain cavity, and it seems to have gone extinct. That leaves either Afarensis or Africanus as being separate lines or branching to Australopithecus Bahrelghazali which then branched to Homo. Only lower jaw bones have been found thus far, but the dentition puts this species closer to Homo than the others. There may have been other branches of Australopithecus, but there is not enough fossil evidence that they were around very long before going extinct. Cross breeding could also have eliminated some differences ("Hominidae_filogenia.png (PNG Image, 1025 ? 979 pixels)."). So me theorists eliminate all of these australopithecines from the homo line of ancestry, believing that homo lines branched off independently from either Ardipithecus Ramidus or A. Garhi. However, one might question this based upon the lack of fossils and the latest find in Georgia on the Black Sea of five Homo Habilis types with a great deal of variation among them. It is possible they are all one species with variation, just as we have today. Speciation generally includes an inability to procreate successfully between species. A recent discovery of what seems to be a new species of Australopithecus, A. Garhi, in Ethiopia is a candidate for early human. This illustration shows the pitifully few pieces that have been found, and the Georgian discovery makes it worth further investigation before ascribing