question_answer 8)

Explain the importance of fossils in deciding evolutionary relationships.

Answer:

Fossils play an important role in deciding evolutionary relationships as follows: (i) The fossils present in the bottom rocks are simple while the most recent fossils found in the upper strata are highly complex. This geographical succession completely agrees with the concept of evolution. (ii) Some fossils provide a direct connecting link between two groups, e.g., study of fossil bird Archaeopteryx indicates that birds have evolved from reptile-like ancestors. (iii) Fossil records of certain mammals (horse, elephant, camel, man, etc.) if arranged according to geological time scale it would present a complete series indicating about their evolution. (iv) Fossils of the dinosaur bodies with feathers have been found in the rocks which were not used for flying by dinosaur but they were meant for giving warmth to the body. These must have evolved into wings later meant for flying as seen in birds. This shows a close relationship between birds and reptiles.