Question

How do fossils provide evidence for the history of life?

Answer 1

The evidence of evolution is one of the fundamental keystones of modern biological theory. It is the only way which can prove all the proposed theories of evolution. We have a number of pieces of evidence to prove biological evolution, namely fossils, comparative anatomy and embryo development patterns.

Complete answer:
Fossils are the remains of the non-degraded parts of living beings found within rocks. The layer from which the fossil is recovered decides the age of the fossil. The fossils found deeper down are older compared to the ones found in the upper layers. They give an idea of the condition of the earth in that specific era. The study of fossils is called palaeontology. Thus, fossils are called paleontological evidence.
It explains that many organisms have the same ancestor and many different organisms evolved as a result of natural selection or genetic drift. Two types of comparative anatomy were observed, namely homologous organs and analogous organs. For example, the limbs of a human, cheetah, whale, and wings of a bat. They all have different functions but have a similar structure indicating a common ancestor.
The embryos of various species show similar structure till a certain period of gestation. For example, the embryos of humans, pigs, reptiles, and birds show similar embryonic development. They develop into the respective species as they grow. This again shows common ancestry.

Note: Homologous organs have the similar structure in different organisms but perform different functions. Thus, it clearly shows a common ancestry. One species gave rise to many other species. This type of evolution is called divergent evolution. Analogous organs have different anatomy but perform similar functions.