Question

What are fossils?
How are they formed?
Describe in brief two methods of determining the age of fossils.
State any role of fossils in the study of the process of evolution.

Answer 1

Hint: When an organism dies and the body decomposes, but when a part of the whole body gets preserved in rocks or any other form it becomes a fossil.

Complete answer: Fossils are the traces of the dead organisms that are now extinct. They are formed as some organisms fail to decay completely, they remain preserved by natural means in some mediums such as sand, mud, rocks, etc.

The fossils age can be determined by:
a. Relative dating method: the relative dating of the fossil is done by the estimation of the position and the rate of their erosion in a particular environment.
b. Absolute dating method: in the absolute dating method is based on the property of the spontaneous decay of unstable radioactive nuclei into the stable radioactive nuclei at a known rate and is constant.
The other two methods of determining the age of fossils are the Uranium-lead technique and the Carbon Dating technique.

The fossils have a significant role in the study of the process of the evolution as they help in creating the evolutionary relationships with present-day organisms and the early organisms

Note: The formation of the sedimentary rocks and dead animals of the sea or lakes get buried in the rocks.