Question

Explain the importance of fossils in determining evolutionary relationships.

Answer 1

Hint: Fossils are the impressions or remains of prehistoric plants and animals that are preserved and embedded in rocks. Fossils provide us with the information and knowledge of animals and plants that lived centuries ago which are now extinct.

Complete answer:
Fossils help us to compare the features of animals that lived during the prehistoric times with their present- day descendants. They provide the missing links in the evolution studies. They help in providing information that helps in forming a sequence of the organisms in the pathway of evolution.
Fossils provide us with evidence about: - The organisms that lived long ago. We can obtain information such as the period during which they lived, their structure, etc by studying the fossils. - Evolutionary development of different species i.e., the line of development and divergence of species. - Connecting links between two groups of organisms. For example, feathers present in certain dinosaurs help in determining their relationship with the birds. Archaeopteryx is an extinct organism that shared characteristics of both animals and reptiles. They had birds- like wings and feathers, but jaws and teeth like reptiles. They also had scaly skin; similar to reptiles. - Fossils also help in identifying the chronology of evolution, i.e. to determine which organisms evolved earlier and which later. - They also help in analyzing the development of complex body structures from simple body designs.

Note: Fossils are just one of the tools in identifying evolutionary relationships. Other tools include excavation, carbon- dating, identifying homologous and analogous structures, and comparing DNA sequences of various organisms. Study of homologous and analogous organs and DNA sequencing help in identifying the branching of different species from a common ancestor.