The work of ......... on population influenced Darwin.

Assertion : Natural selection is the outcome of difference in survival and reproduction among individuals that show variation in one or more traits.
Reason : Adaptive forms of a given trait tend to become more common; less adaptive ones become less common or disappear.

Which factors contribute to the process of speciation?

Why do adaptations occur?

Define the term 'Gene Pool'.

The change of the lighter coloured variety of peppered moth $Biston \text{ } betularia$ to its darker variety $(carbonaria)$ is due to