Evolution is the change in the gene pool of a population in response to various stimuli by a species over time.

Darwin's Theory of Evolution:
Darwin went to the Galapagos Islands and saw that many of the islands had their own unique species of finch. Each of the finches had a beak and body well adapted to the kind of food found on its particular island. They were all different species but looked very similar. Darwin realized that they had evolved from a common ancestor. He proposed that originally a few seed-eating finches had flown to the islands from the mainland. Over millions of years the birds adapted to the foods available on each island and evolved into separate species.


Lamarck's Ideas regarding evolution:
Lamarck's idea is that an organism can pass on characteristics that it acquired during its lifetime to its offspring. Also known as heritability of acquired characteristics or soft inheritance.