Graduate Research Course
Biogeography
Why tapirs live in Malaysia and South America but nowhere in between. Why marsupials dominate Australia. Why Madagascar has lemurs. A rigorous tour from Wallace’s Line to Avise’s phylogeography through the laws that map life onto Earth.
Featured Lectures
What Are The 7 Realms of Biogeography?
The Geography of the Sahara · regional case study
From Deserts to Grasslands · biome transitions and climate gradients
The Secrets of Evolution Revealed · David Attenborough
Tuareg: Warriors of the Dunes · human biogeography of the Sahara
Regional Case Studies
Documentary tours of the realms — Neotropical Amazon, Afrotropical Africa, Indomalayan Himalaya.
AMAZON · Neotropical realm
AFRICA · Afrotropical realm
NEPAL · Himalayan Palearctic–Indomalayan transition
HIMALAYA · Giants of Earth · tectonic / biogeographic divide
UNSEEN TIBET · Palearctic high-altitude plateau
IRAN · Palearctic deserts & Zagros/Alborz mountains
SIBERIA · Palearctic boreal taiga & permafrost
UNSEEN CHINA · Palearctic–Indomalayan mosaic
China’s Hidden Mountain Worlds · high-altitude endemics
The Seven Realms at a Glance
Wallace & Sclater partition of terrestrial life, updated by Holt 2013 using phylogenetic distinctness.
About This Course
Biogeography is the science of why species live where they do. In 1859 Alfred Russel Wallace crossed 32 km of ocean between Bali and Lombok and found the fauna changing from Indomalayan (tigers, primates, deer) to Australasian(marsupials, cockatoos) — a line now named for him. In 1967 Robert MacArthur and E. O. Wilson published The Theory of Island Biogeography, proposing that species richness on islands reflects a dynamic equilibrium between immigration and extinction governed by area and isolation — testable via the power law S = cAz.
The modern discipline weaves together plate tectonics (vicariance), molecular phylogeography (Avise 1987 mtDNA coalescence trees), climate biome modeling (Whittaker 1975; Köppen-Geiger), paleontological range reconstructions, and conservation prioritisation (Myers 2000 biodiversity hotspots). This course covers all nine arcs quantitatively, with Python simulations of the MacArthur-Wilson equilibrium, Kingman coalescent trees, and Hewitt 2000 post-glacial recolonisation waves.
Cross-links: Climate & Biodiversity,Earth Sciences,Ocean Biodiversity,Migration,Origin of Life,Evolution.
Key Equations
Species-Area (power law)
\( S = cA^{z},\quad z \approx 0.2\text{--}0.3 \)
MacArthur-Wilson Equilibrium
\( \lambda_I(S) = \mu_E(S) \)
Immigration Rate
\( \lambda_I(S) = I_0(1 - S/P) \)
Extinction Rate
\( \mu_E(S) = E_0\,S/P \)
Molecular Clock
\( d = 2\mu t \)
Coalescent Time (neutral)
\( E[T_2] = 2N_e \)
Nine Modules
M0
History & Foundations
Humboldt 1807 plant-altitude zonation, Wallace 1859-1876, Darwin Beagle 1839, Wallace's Line, Lyell Principles of Geology, Sclater 1858 six ornithological regions.
M1
The Seven Realms
Palearctic, Nearctic, Afrotropical, Neotropical, Indomalayan, Australasian, Oceanian, plus Antarctic. Holt 2013 phylogenetic-based redefinition; Wallace-Weber-Lydekker lines.
M2
Island Biogeography
MacArthur-Wilson 1967 equilibrium theory, species-area S = cA^z, immigration-extinction balance, Galapagos, Hawaii, Krakatau recolonization, Simberloff mangrove experiments.
M3
Continental Drift & Vicariance
Wegener 1912, plate tectonics 1960s confirmation, Gondwana breakup, Great American Interchange 3 Mya, Bering land bridge, marsupial-placental split, cladistic vicariance (Croizat).
M4
Dispersal Biogeography
Long-distance over-water dispersal (rafting, anemochory, zoochory), Darwin seed-salt-tolerance experiments, Hawaiian silversword radiation, Gilbert-Cotroneo Galapagos finch.
M5
Biomes & Climate
Koppen-Geiger classification, Whittaker 1975 temperature-precipitation biome plot, tropical/temperate/boreal/tundra/desert/Mediterranean, latitudinal diversity gradient (Hillebrand 2004).
M6
Phylogeography & Clocks
Avise 1987 phylogeography, mtDNA tree-building, coalescent theory (Kingman), molecular clock calibration, Pleistocene refugia, Hewitt 2000 European glacial retreats.
M7
Paleobiogeography & Extinctions
Cambrian explosion 540 Mya, Permo-Triassic 250 Mya (96% marine extinction), K-Pg 66 Mya Chicxulub, Pleistocene megafauna Martin overkill hypothesis, Sepkoski diversity curves.
M8
Conservation & Anthropocene
Myers 2000 biodiversity hotspots (36 today), invasive species flows, homogenization (McKinney 2006), climate-driven range shifts, assisted colonization ethics, 30x30 target.
Recommended Textbooks
- [1] MacArthur, R. H. & Wilson, E. O. (1967). The Theory of Island Biogeography. Princeton University Press.
- [2] Lomolino, M. V., Riddle, B. R., Whittaker, R. J. & Brown, J. H. (2016). Biogeography, 5th ed. Sinauer.
- [3] Avise, J. C. (2000). Phylogeography: The History and Formation of Species. Harvard University Press.
- [4] Wallace, A. R. (1876). The Geographical Distribution of Animals. Macmillan.
- [5] Whittaker, R. H. (1975). Communities and Ecosystems, 2nd ed. Macmillan.
- [6] Myers, N. et al. (2000). Biodiversity hotspots for conservation priorities. Nature, 403, 853–858.
- [7] Holt, B. G. et al. (2013). An update of Wallace’s zoogeographic regions of the world. Science, 339, 74–78.