GGR305H1 Lecture Notes - Lecture 7: Insular Biogeography, Island, Survival Island
10 Apr 2019
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Document Summary
So far in biogeography we"ve examined four fundamental processes: Dispersal: movement of organisms from a point of origin (location of source, or ancestral population) to a new location. Colonization: organism reaches new location, survives, reproduces, and established new population. Extinction: species is eliminated from a particular areal (no more reproducing individuals present) species may survive elsewhere, and may re-colonize area where it went extinct. Local extinction allow for new dispersal and colonization. Evolution: surviving population in a particular area undergoes changes in frequency of gene alleles; may result in altered phenotype, and, given sufficient time, possibly the formation of new species (= speciation) Islands can serve as a laboratory for the study of biogeography. The biota of an island is simpler than that of a continental area, and the interactions are easier to understand. Islands also provide one of the essential necessities for speciation: isolation. Darwin"s ideas about evolution were strongly influenced by the diversity he observed on islands.
