Final answer:
Fossils are the preserved remains of ancient humans, animals, or plants, studied by scientists to learn about prehistoric life, though the fossil record is incomplete.
Step-by-step explanation:
The preserved remains of ancient humans, animals, or plants are called fossils. These remains can include bones, teeth, impressions, or even organic molecules. Biological anthropologists and paleontologists study these fossils to understand the characteristics and evolution of species from the distant past. Favorable conditions for fossil preservation include environments with volcanic ash, limestone, and mineralized groundwater, but the fossil record is quite incomplete. Moreover, rare examples of unaltered fossils can be found in amber, tar, ice, or as mummified remains, offering valuable insights into prehistoric life.