1. In what ways are the remains of Sahelanthropus and Ardipithecus primitive? How do we know that these forms are hominids? How sure are we?
They had a flat cranial base and relatively thin enamel caps on the molar teeth. From measurements of the humerus, body weight for one of the individuals is estimated at 42 kg; if this bone comes from a male individual, this weight estimate is very similar to that hypothesized for other early hominids.
We are sure, presently at least, as we have top scholars in Physical Anthropology who maintain this claim (mainly Jurmain and Kilgore…)
2. Assume that you are in the laboratory analyzing the “Lucy” A. afarensis skeleton. You also have complete skeletons from a chimpanzee and a modern human. Which parts of the Lucy skeleton are more similar to the chimpanzee? Which are more similar to the human? Which parts of the Lucy skeleton are most informative?
A. afarensis was a short hominid, as indicated by Lucy. The upper limbs of Lucy are longer than in modern humans and in addition other A. afarensis fossils indicate that the wrist, hand, and foot bones show several differences from modern humans. This suggests that Lucy was more than likely a terrestrial biped that also had the capability of climbing about quite ably in the trees. Further, Lucy's teeth do appear to share more primitive features with other early hominoids and with living apes than with later hominids.
The most informative parts would be her teeth, cranial skull parts, pelvis, and limbs. The teeth provide information on her being an early primitive hominid species, while her cranium parts indicate a small capacity. The pelvis indicated her sex, and the limbs were proof that she walked bipedally while on the ground as well as still had the ability to climb and move about in the trees.
No comments:
Post a Comment