Explanation

Darwin’s evidence for evolution: Biogeographic distributions (i) Environment cannot account for either similarity for dissimilarity, since similar environments can harbor entirely different species groups (ii) Affinity (similarity) of groups on the same continent (or sea) is closer than between continents (or sea) (iii) Geographical barriers usually divide these different groups, and there is a correlation between degree of difference and rate of migration of ability to disperse across the barriers