Theory of Dispersal (Darwinian) Biogeography
1. Species evolves in one area (center of origin)
2. Disperses outward from this center of origin (usually crosses a barrier).
3. Subsequent evolution produces a new species (allopatric speciation).
BARRIER IS OLDER THAN ANCESTRAL SPECIES
Significant in that geology was irrelevant to Darwin’s theory, except as a center of origin: PROCESSES of evolution were driving organismal distributions, rather than geological factors.