CBSE Class 10 Answered

Fossils are the preserved remains or traces of animals, plants, and other organisms from the remote past.

Fossils are an important piece of proving the theory of evolution because they present the physical proof of its' existence. We know that life has evolved by looking at fossils. Paleontologists examine the fossil record in order to understand the process of evolution and the way particular species have evolved.

When we dig into the Earth and start finding fossils, it is reasonable to suppose that the fossils we find closer to the surface are more recent than the fossils we find in deeper layers. This gives us an idea of the relative times these organisms existed on Earth. 

A study of fossils in different sedimentary layers indicates the geological period in which they existed. This study shows that life-forms varied over time and certain life forms are restricted to certain geological time-spans.  Hence fossils are instrumental in tracing the process of evolution

The fossil record and faunal succession form the basis of determining the age of rocks based on the fossils they contain. The geologic time scale was developed based on the relative ages of rock strata as determined by the early paleontologists and stratigraphers. Also, the study of fossils can more specifically pinpoint when and in what organism branching occurred in the tree of life.

Fossils are our only clues to life in the past. They help us learn about evolution - how living things have changed through time. Fossils are like a photograph of an animal at a particular point in the history of the Earth.

Fossils also help us understand what kinds of environments existed millions of year ago.