Biological anthropologists primarily, although not exclusively, study fossil artifacts. A fossil is any remainder of a plant or animal that has been preserved in the earth. Upon the death of an organism, its body slowly decomposes until all that remains are the teeth and the bones or a mere impression of the organism’s original form. Under most conditions, teeth and bones and impressions eventually deteriorate, too. However, occasionally conditions are favorable for preservation. Examples of favorable materials for fossil formation include volcanic ash, limestone, and mineralized groundwater. Scientists do not have fossils of everything that lived in the past, and in some cases, remains from only a few individuals of a species have been found. The fossil record is very incomplete. Robert Martin, a curator at the Field Museum of Natural History in Chicago, estimates that there have been more than 6,000 primate species, while the remains of only 3 percent have been found. Fossils are very rare, but they are extremely informative about human biological evolution.
The content of this course has been taken from the free Anthropology textbook by Openstax