Historical Figures
Historical Figures:
Carolus Linnaeus
Believed life radiated from a “Paradisical Mountain” in the tropics (likely an island)
Second radiation (Noah’s landing) from Mt. Ararat
Modes of dispersal possessed by organisms allowed this
Described ~13,000 species
~ 4,200 animals
~ 9,000 plants
George-Louis Leclerc, Comte de Buffon (1707-1788)
Earth is much older than 6,000 years
Taxa changed throughout time
The earth has also changed through time
There is a connection between geological and biological histories of earth
Hypothesized that the centre of origin for Earth’s biota was in the far north (not a tropical island)
Occurred when climatic conditions were more benign
Biotas changed and diversified as they colonize southward
Early foundations of natural selection
Buffon’s law (First law of biogeography):
Environmentally similar but isolated regions have distinct species assemblages
But species have similar attributes
Buffon only considered birds and mammals
Johann Reinhold Forster (1729 - 1798)
Developed a systematic global view of botanical regions, each with its own distinct assemblages
Support for Buffon’s Law (added plants)
Recognized relationships between plants and environment (abiotic and biotic; animals)
Noted the tendency for plant diversity to decreased from the equator to the poles
Early insights into what would become theories of island biogeography and species diversity
Alexander von Humboldt (1769-1859)
Founder of phytogeography
Founded volcanology, anthropology, meteorology, geomagnetism, oceanography, archaeology
Suggests that South American and West African coastlines matched, and suggested they may have once been joined
Coined term “vegetation belts”, promoted idea that climate change determines plant distributions
Altitudinal vegetation belts:
Desert scrub
Woodland
Subalpine
Alpine
Noted that latitudinal variation is similar to elevational variation
Augustin de Candolle: (1778 - 1841)
Competition for resources influences distribution
Built on work of forester
Island area, isolation, age, volcanism, and climate influence floristic activity
Charles Lyell (1797 - 1875)
Principles of geology
Stratigraphic layers and fossils suggest Earth and its biota changes through time
Changes are gradual and ongoing
Uniformitarianism: natural processes observed currently have always acted on Earth, and are key to understanding the past
Extensionist
Charles Darwin (1809 - 1882)
Influenced by Lyell
Dispersalist
Made connection between Earth’s geological history and changes in biota as the result of geographic isolation and natural selection
On the Origin of Species (1859)
Proposed natural selection as a key factor in speciation and differences in species diversity and composition across geographical space
Joseph Dalton Hooker (1817 - 1911)
Believed similarities between African and S. American floras were the result of a once exposed land bridge
Continental drift theory (plate tectonics) would later help explain Hooker’s observations
Proponent of what would become island biography
Alfred Russel Wallace: (1823 - 1913)
Darwin defined “Origin” for 15 years as he amassed evidence
Wallace sent Darwin a manuscript with identical theory based on similar observations
This forced Darwin’s hand, and he published before Wallace
E.W. Hilgard: (1833 - 1916)
Founder of soil science
Climate and plants are responsible for converting parent material into soil
Vasily V. Dokuchaev (1846 - 1903)
Soils have characteristic structure
Louis Agassiz (1807 - 1873)
Founder of glaciology
Theory of the “Ice Age”
Did not accept Darwin’s theories
Clinton Hart Merriam (1855 - 1942)
Coined the term “biogeography”
Confirmed that elevational variation in plant species composition were generally similar to latitudinal variation
Life zones
Ernst Mayr (1904 - 2005)
Biological Species concept: a species is definable as a group of populations that are reproductively isolated
Alfred Lothar Wegener (1880 - 1930)
Theory of continental drift , 1912
Continents once joined, now drifting
Landmasses fit together like a jigsaw
Geological and fossil similarities between matching sides of continents
Widely accepted by the 1960s
G. Evelyn Hutchinson (1903 - 1991)
Studied diversity and species coexistence
Multidimensional niche concept
Robert H. MacArthur & Edward O. Wilson:
Theory of island biogeography: island size and species diversity are correlated
James H. Brown
Founder of macroecology: study of large scale questions about distribution of body size, abundance, and geographic range of organisms
Cofounder of metabolic scaling theory, which offers mechanism for many biogeographical and macroecological patterns