Question

Define the term fossil and give its significance in evolution.

Answer 1

Hint: The remnants or traces of animals and plants can be found on the rocks and earth crust. This imprint tells us about the plants and animals found in the past. They are preserved in rocks as fossils.

Complete Answer:
A fossil is the remains of the once living organisms on the earth crust which can be in any form like imprints, remnants, bone, exoskeleton or even DNA. These remains can be seen in rocks, wood or even earth crust.

The fossils are formed when the organism dies and it gets buried in a mud or silt. After the decomposition, the bone and shells are left behind and deposited as sediments over the rocks.

Significance:
- Fossil records are the history of how evolution has taken place. It tells us about the life forms which existed in the prehistoric eras and how they have undergone changes and modification with respect to time and other environmental changes. It helps in determining the evolutionary relationship between organisms.
- Also the study of fossils has been useful in determining the connecting link between the organisms. For example Archaeopteryx an extinct animal was found as the connecting link between animal and reptiles.

Additional Information: The oldest fossil found is around 3.38 billion years old to 4.1 billion year old. The age of foil can be calculated by a method called the carbon dating.

Note: Palaeontology is the branch of science which deals with the study of fossils. It analyses the complete detail like age, method of formation, and evolutionary significance. The specimen is considered a fossil if its age is over 10000 years.