Biogeography

Paradisaical Mountain All life originated at this mountain at equator Species dispersal hypothesis Species creation at North Pole during warm period

Latitudinal diversity gradient Diversity decreased equator to pole Elevation diversity gradient Diversity decreases at higher elevations Wallace's line Biogeographic divide that separates Asian and Australian species Island diversity Island size is correlated to species richness Bergmann's rule Colder = larger

Vicariance Barrier splits a population Dispersal Organisms move across barriers to colonize new areas, still lead to isolation Extensionists land bridges move them

Evidence for variance vs dispersal Phylogeny Are species in different regions, sister taxa? Is the distribution congruent across multiple clades Divergence times after geological separation: dispersal more likely before: variance Fossil evidence ancestral forms present before regions separated?

Endemic: native

Island biogeography closer island, larger size = more species richness far island, small island = more extinction