AP BIOLOGY

Detailed explanation-1: -He collected many specimens of the finches on the Galapagos Islands. These specimens and his notebooks provided Darwin with a record of his observations as he developed the theory of evolution through natural selection.

Detailed explanation-2: -After the Beagle returned to England in October 1836, Darwin began reflecting on his observations and experiences, and over the next two years developed the basic outline of his groundbreaking theory of evolution through natural selection.

Detailed explanation-3: -More individuals are produced each generation that can survive. Phenotypic variation exists among individuals and the variation is heritable. Those individuals with heritable traits better suited to the environment will survive.

Detailed explanation-4: -In Galapagos he found a remarkable population of plants, birds and reptiles that had developed in isolation from the mainland, but often differed on almost identical islands next door to one another and whose characteristics he could only explain by a gradual transformation of the various species.