Biogeography
has a prehistoric origin dated back to primitive cavemen who searched certain areas for food, born from the suspicion that our species was affecting change on distribution of other species, began to appear in titles in the 60's and 70's, is a 200 year old science, is closely associated with the idea of evolution, and is not an experimental science but instead uses inductive reasoning by recognizing patterns and proposing a general mechanistic explanation since spatial and temporal scales are not conducive to experimentation
Who were the first well known biogeographers?
Darwin and Wallace
Biogeography (official definition)
the science that attempts to document and understand spatial patterns of biological diversity
Phylogeography
the science that attempts to document and understand temporal patterns of biological diversity
For example, in island biology, the Island of Surtsey (20 miles from the mainland of Iceland)
is a nature reserve for scientists to document species distribution
Uniformitarianism
the principle that the same natural laws and processes that operate in the universe now, have always operated in the universe in the past and apply everywhere in universe i.e. "the present is key to the past
From 1830 to 1833 Charles Lyell's Principles of Geology
was published as an attempt to explain the changes of the Earth's surface by references to causes now in operation
4 related propositions
Uniformity of law (laws of nature constant in time and space), Uniformity of Methodology (the appropriate hypotheses for explaining the geological past are those with analogy today), Uniformity of Kind (past and present causes are all same kind, have the same energy, and produce the same effects), and Uniformity of degree (geological circumstances have remained the same over time)
Exceptions due to
meanings attached to concept
The opposing view is catatrophism which is
where earth is affected by sudden, short-lived violent episodes
Evolution
constantly at work making small changes gradually (e.g. mutations) and changes selected "for" or "against" based upon reproductive success within certain time and environment
Punctuated Equilibrium
speciation occurs in spurts of major genetic alternations that punctuate long periods of little change
Current Journals for Biogeography Literature
Journal of Biogeography (1973), Ecography (1978), Global Ecology and Biogeography (1981), and Diversity and Distributions (1998)
Biogeography (2 branches)
connected to 2 different branches: evolutionary biology and ecology
Biologists and naturalists regularly accompanied 18th and 19th century exploration expedition during
the age of European exploration
Who is also a well known biogeographer?
Aristotle
18th century naturalists and biologists were largely creationsists and
believed that the earth, its climate, and species are considered immutable
James Ussher
was the leader of the church of Ireland and one of the first scholars of Trinity College of Dublin, wrote annales veteris testament a prima mundi origine deducta (1650) a chronology of the bible and dated creation as 10/23/4004 B.C.
Ussher's dates were used by
William Jennings Bryan in the Scopes' monkey trial (1925)
Problems originating during the age of exploration
inadequate system of naming and categorizing the rapidly growing number of species, too many species to have been accommodated by the biblical Noah's ark, and adapted to different climates and areas
Carolus Linnaeus (1707-1778)
created binomial nomenclature (2 name naming system), described equatorial "paradisaical mountain" in which species adapt to environmental conditions along the slope before the continents divided, and Noah's ark came to rest on Mt. Ararat
Georges-Louis Leclerc (1707-1788)
was a French man who believed that the same climate and environments could be inhabited by very different organisms and Linnaeus' spread of life required the traversing of some inhospitable environments such as northern forest species would have to migrate away from deserts
The Lewis- Clark Expedition
was President Jefferson's response to the words of the French scientist Buffon and was one of the most ambitious biogeographic surveys in history
Buffon's Law
environmentally similar but isolated regions have distinct assemblages of mammals and birds (the 1st principle of biogeography)
James Cook
was an explorer, navigator, and cartographer for the British navy on the H.M.S. Endeavor and had 3 major Pacific voyages thus discovering many islands and chains
Johann Reinhold Forster
described the relationship between regional floras and environmental conditions and how animals' associations changed with those of plants, noted that insular (island) communities had fewer plants species than those on mainland and the tendency for plant diversity to decrease from the equator to the poles
Alexander von Humboldt (1769-1859)
the father of phytogeography, noted that the floristic zones described by Forster along latitudinal gradients could be observed at a more local scale along elevation gradients, and invented isobars and isotherms to show plants were distributed in elevation zones or floristic belts
Augustin de Candolle (1788-1841)
discovered resource availability, was one of the first to write about competition, and was a friend of Jean Baptiste de Lamarck and George Cuvier
3 Important Advances of the 19th Century
a better estimate of the Earth's age (few thousand to millions of years), a better understanding of the dynamic nature of continents and oceans (continental drift and plate tectonics), and a better understanding of the mechanisms spreading and diversifying species
Adolphe Brongiart (1801-1876)
the father of paleobotany", was a French specialist on the classification and distribution of fossil plants
19th century giants who stood on the shoulder of other giants
Charles Darwin, Joseph Hooker, Phillip Sclater, and Alfred Wallace
Charles Darwin's and Alfred Wallace's papers on evolution
were jointly read at the Linnaean society (1858)
Extensionists vs. Dispersalists
Extensionists (ex: Louis Agassiz, Charles Lyell, and Robert Hooker) vs. Dispersalists (ex: Charles Darwin)
Extensionists vs. Dispersalists continued
Extensionists believed that the species extended its range on its own while Dispersalists believed that there was a random dispersal of each species
Phillip Sclater (1829-1913)
was one of the few early zoologists to make significant contributions to biogeography, good friend of Darwin, an eminent ornithologist who described 1067 species, 135 genera, and 2 families, proposed a scheme that divided the Earth in biogeographic regions still used today, 5 land biotic regions for birds: palearctic, aeteopica, indica, neotropica, nearctic, and australiana, and 6 marine regions for marine mammals
19th Century Name Rules (Laws)
C.W.L. Golger= within species individuals in moist humid climates are darker, C. Bergmann= for warm blooded animals those in colder climates are larger, J.A. Allen= for warm blooded animals those in colder climates have shorter limbs and appendages, E.D. Cope= groups tend to evolved in one direction e.g. larger body size with time, and Guthrie-Geist= for larger mammals more food yields larger animals (island dwarfing)
Allometry
biological scaling, how the characteristics of living creatures change with size (e.g. more aggressive, less social, anatomy, physiology, etc.)
Macroecology
study of large scale diversity patterns, ecosystems, and worldwide patterns
Orthogenesis
theory that evolution continues only in one direction (i.e. uni linear) and that this orientation is an intrinsic property of the organism and not controlled by natural selection so "evolution in straight lines", ex: horse lineage
Another example of orthogenesis is
the Irish Elk (Megaloceros) which is 7' tall at shoulders , has antler span of 12', and evolved during glacial periods of the last million years (pleistocene), last one was in Ireland about 11,000 years ago
C. Hart Merriam (1855-1942)
was a Yale educated MD but became a naturalist, had extensive field studies in the SW area of the US, and came up with "life zones
Louis Agassiz
father of glaciology", was a swiss emigrant to America and Harvard professor, refused to accept Darwin's theory on the mutability of species, in 1840 developed the first comprehensive theory of the "Ice Age" after studying the glaciers in his home town in the Alps
Edward Forbes (1815-1854)
father of oceanography", was a professor at the University of Edinburgh, first comprehensive work in marine biogeography, and divided marine world into 9 regions of similar fauna
First Half of the 20th century
advances in paleontology sparked great debates over past and present theories, newly proposed land bridges, sunken continents, and drifting continents fueled arguments with no consensus in sight, and Ernst Mayr made major contributions during this time to the fields of systematics, evolution, and historical biogeography (phylogeography)
Since the 1950's four major developments are
plate tectonics, new phylogenetic methods, new techniques in ecological biogeography, and investigations of the mechanisms that limit distribution
Plate Tectonics
until the 1960's contemporary wisdom: the Earth's crust is fixed with no lateral movement, originally introduced by Antonio Snider-Pelligrini (1858), resurfaced in 1910-1912 with German meterologist Alfred Wegener and American geologist F.B. Taylor, and geological evidence for plate tectonics became irrefutable by the 1960's and biogeographers had to rethink many of their conclusions
Phylogeography with the advent of DNA technology tracing histories and relationship
has improved, DNA sequence comparisons are being used to address old problems of "disjunction" (two closely related species are widely separated in space aka vicarant species)
Ecological Biogeography
ecologists began to emphasize the importance of competition, predation, and mutualism in distribution patterns, and processes that determine diversity
Theoretical Biological Question: Are the dispersal, establishment, and radiation of a species stochastic (random) or deterministic (predictable)?
The answer is both in the medium
Cenozoic Era
Quaternary Period 1.8 million years ago and Tertiary Period 65 million years ago
Mesozoic Era
Cretaceous Period 144 million years ago, Jurassic Period 206 million years ago, and Triassic Period 248 million years ago
Paleozoic Era
Permian Period 290 million years ago, Pennsylvanian Period 323 million years ago, Mississippian Period 354 million years ago, Devonian Period 417 million years ago, Silurian Period 443 million years ago, Ordovician Period 490 million years ago, and Cambrian Period 543 million years ago
Precambrian Era
Proterozoic and Archean Periods 2.5 billion years ago