A Historical Overview of Biogeography: From Aristotle to Contemporary Theories, Slides of Geology

Download A Historical Overview of Biogeography: From Aristotle to Contemporary Theories and more Slides Geology in PDF only on Docsity! The history of biogeography Docsity.com Prehistory Humans have always used biogeographic knowledge Docsity.com Age of European Exploration Carl Linnaeus (1707- 1778) • Species classification system (hierarchical, binomial) – Kingdom – Phyla – Class – Order – Family – Genera – Species • Species are immutable • Hypothesis to explain biodiversity distribution: Paradisical Mountain Docsity.com Age of European Exploration Linnaeus’ Paradisical Mountain Hypothesis • All species housed on slopes of equatorial mountain-island ~6000 years ago • Flood receded, continents expanded, terrestrial species expanded to new sites • In accordance with biblical events (Noah’s Ark, biblical timeline) and biblical beliefs (species do not change; later abandoned this idea) Docsity.com Age of European Exploration Georges-Louis Buffon (1707-1788) • Studied live and fossilized mammals • Believed in a single species creation event • Recognized climatic shifts & their importance to understanding species spread • Critique of Linnaeus: – Different regions (even with same environment) often had different species – If species were incapable of adaptation, they could not have traveled through hostile environmental barriers from a single Docsity.com Age of Enlightenment • Lots of data regarding species diversity and global distribution had been gathered • Sought rational explanations for & conceptual understanding of observed patterns of biodiversity Docsity.com Age of Enlightenment Alexander von Humboldt (1769-1859) • Father of phytogeography • Covariation of vegetation and climate • Invented isobar and isotherm • Expanded latitudinal biodiversity gradients into elevational gradients Docsity.com Age of Enlightenment Agustin de Candolle (1778-1841) • Species competition for resources as a key factor for species persistence • Factors other than island area influence biodiversity: isolation, climate, geological history, age Docsity.com Charles Darwin (1809-1882) • 1831 – 5 year voyage on HMS Beagle to South America • Collected samples of rocks, plants, animals, fossils • Developed the theory of evolution by natural selection; The Origin of Species (1859) • Emphasized importance of long- distance dispersal in biogeographic distribution of species Darwin in 1840 Docsity.com Darwin’s voyage Argentina – discovered large mammalian fossils Galapagos – fascinating wildlife Docsity.com Argentinian Fossils Giant ground sloths Giant armadillo-like creatures k “ Docsity.com Galapagos Finches 1, Geospiza magnirostris, 2. Geospiza fortis. 3. Geospiza parvula, 4. Certhidea olivacea. Docsity.com  • Finches and tortoises - different islands, different appearance • Darwin could not connect biblical views with natural evidence • Darwin concluded – species change over time!! One finch and tortoise diversified to many species • Remembered fossils – concluded they were ancestors of current armadillo and sloth Docsity.com Did embryonic stages of animals have characteristics of ancestors? Ontogeny recapitulates phylogeny – Whales had teeth (descended from sea creatures with teeth?) – Snakes had rudimentary legs (descended from lizards?) – Human have structures similar to gill (descended from fish?) Species were related in “tree of life” Docsity.com • Species are not immutable, but dynamic responding to biotic/abiotic factors • But what explains the geographic distribution of species? -cosmopolitan vs. disjunct species • Debate: Dispersalists vs. Extensionists – Dispersalists - Long-distance dispersal events (Darwin) – Extensionists - Landbridges connecting continents (lack of evidence; Lyell) • Further study of dispersal ecology and greater understanding of geological processes (e.g. continental drift) would help settle dispute Docsity.com First half of the 20" century (®) Docsity.com Alfred Wegener (1880-1930) • Theory of continental drift - 1912 (first introduced by Antonio Snider- Pelligrini in 1858) • Not widely accepted until the 1960s • Revolutionized biogeography – rethink reasons for species distributional patterns Docsity.com G. E. Hutchinson (1903-1991) • Multidimensional niche concept • Mechanisms of species coexistence • Father of Limnology Docsity.com Late 20th century Docsity.com Robert H. MacArthur (1930-1972) • Mathmatician & theoretical ecologist • Strong emphasis on hypothesis testing Edward O. Wilson (1929 – ) • Naturalist & evolutionary biologist • Global biodiversity and conservation Theory of Island Biogeography - Mechanistic explanation of species richness - large islands close to mainlands have greater biodiversity than small, isolated islands Docsity.com