Essentials of Physical Anthropology Study Set 2
Quiz 8 :
Primate and Hominin Origins
Paleoanthropology deals with the study of evolutionary relationships of early humans. It is a diverse interdisciplinary hunt where we study about the different aspects of the early humans. Various methods have been developed to estimate the time period of the human fossils. The two broad classifications of paleoanthropology are relative dating and chronometric dating. Chronometric dating is also called as absolute dating. Relative dating tells about the fossil's relative position strata and the relationship with time scale. It is based on the principle of stratigraphy, so it is called as stratigraphy dating. Chronometric dating deals with the methods to find the age of the fossil precisely. It is better to use the chronometric dating method as it tells the age and time period of the human fossil with more precision and accuracy. It is based on the principle of radioactivity. The most important method of chronometric dating uses potassium-40 ( ) which produces argon-40 ( ) and has a half-life of 1.25 billion years. One of the relative dating techniques is biostratigraphy. It is based on the principle of relative stratification of different structures of the fossils. The fossils which are found away from the ground level are said to be older than the ones found near the ground level.
Fossils help to investigate the evolution and relationship between their nearest relative. The fossil's study can help in reconstructing the anatomy, behavior, and evolution of an extinct organism. Fossil preserved in rock can be extracted by using acid. Sahelanthropus is an extinct species of hominin. It was dated about seven million years ago. They might have walked on two legs. No postcranial are known in them. Ardipithecus is an extinct species of hominin and is one the earliest ancestor for humans. Sahelanthropus and Ardipithecus serve as the ancestor of humans and were the intermediate within people and apes. These are similar enough biologically to be considered from the same tribe of biology. As they were upright walkers and two-footed (bipedal) this feature makes them be classified as hominins.
Australopithecus afarensis lived around 3.9 to 2.9 million years ago. It is an extinct of hominin species. It was built slender and is the most closely relates species of the Homo sapiens. (a) The parts of Australopithecus afarensis that are similar to the chimpanzee are as follows: 1. Prognathic faces 2. Small brains 3. Arms 4. Hands 5. Brow ridges (b) The front teeth of afarensis were large like the humans, but their canine teeth did not project beyond others. Their teeth suggest that their diet included some meat and some soft food. It serves as the most informative portion of the afarensis.