GEOLOGY

Detailed explanation-1: -Evolution is a gradual change occuring in living organisms over a long duration.

Detailed explanation-2: -Evolution is a gradual process in which something changes into a different and usually more complex or better form. The mechanisms of evolution include natural selection acting on the genetic variation among individuals, mutation, migration and genetic drift.

Detailed explanation-3: -Evolution is a gradual and continuing process of change that occurs over a period of time, due to slight variations in genetic compositions as well as changes in environment, leading to formation of new species.

Detailed explanation-4: -Evolution is the sequence of gradual changes, which take place in primitive organisms over millions of years, due to which new species are formed.