Map from Holt et al. (2013) Science Terrestrial Zoogeographic Regions Published as “an update of Wallace’s zoogeographic regions” Biogeography

Diversity Gradients Birds Map from Hawkins et al. (2006) J. Biogeogr.

Map from Willig et al. (2003) Ann. Rev. Ecol. Evol. Syst. Biogeography Diversity Gradients Mammals

Image from staffwww.fullcoll.edu Biogeography Diversity Gradients – Vascular Plants

The study of variation in species composition & diversity among geographic locations Biogeography Painting (1843) of Alexander von Humboldt & plate from his Geography of Plants (1805) from Wikimedia Commons

Local community A Regional community Global community Drift, Selection, Speciation Drift Selection Speciation Dispersal Local community B Drift Selection Speciation Redrawn from Vellend & Orrock (2010) Dispersal Community Assembly Drift, Selection, Speciation

Global diversity Hierarchy of Scales of Diversity Regional-scale diversity or Regional species pool or Gamma diversity (  ) Community B Local- scale diversity or Alpha diversity (  ) Community A Local- scale diversity or Alpha diversity (  ) *Beta diversity (  ) *Beta diversity reflects species turnover Original concept from Whittaker (1975)

Indirect Assessment of Local vs. Regional Influences Cain, Bowman & Hacker (2014), Fig to 1 Proportionate increase; regional processes dominate over local processes Saturation; local processes limit local richness

West Gulf Coastal Plain East Gulf Coastal Plain Atlantic Coastal Plain Subtropical Coastal Plain Longleaf pine transition woodlands Longleaf pine bluestem savannas Longleaf pine wiregrass savannas South Florida slash pine savannas Longleaf-slash pine wiregrass savannas From Jean Huffman, after Platt (1999) Appalachian Plateau Valley and Ridge Piedmont Plateau Blue Ridge Found nowhere else 1630 endemic plant species on Southeastern Coastal Plain (Sorrie & Weakley 2001 Castanea) Endemism E.g., parrot pitcher plant

Continental Drift Cain, Bowman & Hacker (2014), Fig ; concept generally attributed to Alfred Wegener (1912)

The mechanism for continental drift Plate Tectonics Cain, Bowman & Hacker (2014), Fig Main types of boundaries between plates: Mid-ocean ridge Subduction zone Fault

Dispersal spread these organisms across Gondwana ~150 mya, but vicariance separated their fossils across continents Vicariance = continuous geographic range rendered discontinuous by the emergence of a barrier Dispersal vs. Vicariance Map from Wikimedia Commons

Molecular phylogenetic evidence suggests that the ratite common ancestor roamed across Gondwana, but populations diverged as continents separated (i.e., vicariance) However, kiwis appear to have originated in Australia, then dispersed to New Zealand Dispersal vs. Vicariance Cain, Bowman & Hacker (2014), Fig

Cain, Bowman & Hacker (2014), Fig Area, Isolation, Evolutionary History (e.g., Time, Stability) & Productivity Explanations for Origins of Regional Diversity Gradients Diversification rate = (Speciation rate) – (Extinction rate) Cradle effect = Higher speciation rate Museum effect = Lower extinction rate

Cain, Bowman & Hacker (2014), Fig Area, Isolation, Evolutionary History (e.g., Time, Stability) & Productivity Explanations for Origins of Regional Diversity Gradients

Cain, Bowman & Hacker (2014), Fig Area, Isolation, Evolutionary History (e.g., Time, Stability) & Productivity Explanations for Origins of Regional Diversity Gradients

Map from Area, Isolation, Evolutionary History (e.g., Time, Stability) & Productivity Explanations for Origins of Regional Diversity Gradients

Cain, Bowman & Hacker (2014), Fig Area, Isolation, Evolutionary History (e.g., Time, Stability) & Productivity Explanations for Origins of Regional Diversity Gradients

Species-area curves from Rosenzweig (1995) Species-Area Relationship

Figure from Hubbell (2001, pg. 158) Species-Area Relationship Slope changes across scales

Data for Bismark Archipelago birds from Diamond (1972) PNAS Species-Isolation Relationship

The influence of area & isolation on local species richness Island Biogeography Theory Cain, Bowman & Hacker (2014), Fig ; MacArthur & Wilson (1967) The Theory of Island Biogeography