Question

Define evolution? How does it occur? Describe how fossils provide us evidence in support of evolution

Answer 1

The slow change in the body design of an organism over a long period of time is termed as evolution. It helps an organism to survive in its surroundings. 

Evidences of Evolution 
Fossils − They represent plants and animals that lived millions of years ago and are now extinct. Different aged rock sediments contain fossils of different life-forms, which probably died during the formation of the particular sediment. 
Comparative anatomy and morphology − It shows evidences of the similarities and differences between living forms of today and that of the prehistoric times. Some of the examples of comparative anatomy and morphology are: 
Homologous organs − All mammals share the same pattern of forelimbs. Though they perform different functions, they are anatomically similar. This is called divergent evolution and the structures are called homologous structures (common ancestors). 
Analogous organs − The pair of organs is not anatomically similar, but performs the same function (e.g., the wings of butterflies and birds). This is called convergent evolution .

Answer 2

evolution is the gradual changes from simple life forms to complex life forms.
fossils says about the changes in environment along hierarchy of organisms