http://www.uvm.edu/~ngotelli/musicpage/Simberloff/SimberloffII.jpg Dan Simberloff Ryan Eldridge http://newsroom.ucla.edu/portal/ucla/artwork/4/2/5/9/2/242592/Jared_Diamond_1.jpg http://eeb.bio.utk.edu/wp-content/uploads/sites/4/2013/02/Simberloff.jpeg Simberloff vs. Diamond • Diamond (1975) postulates 7 “assembly rules” governing communities based on field observations of bird distributions in the Bismarck Archipelago • Attributes certain rules largely to competition http://www.ibiblio.org/hyperwar/USMC/USMC-M-NBrit/maps/USMC-M-NBrit-2.jpg Assembly Rules Assembly Rules • Connor & Simberloff (1979)…don’t agree • “At least one of the assembly rules is untestable, three are tautological consequences of definition plus elementary laws of probability, and the remaining three describe situations which would for the most part be found even if species were randomly distributed on islands.” (Connor & Simberloff 1979) • “That such an all-encompassing theory should be built on so little evidence invites an examination of the procedures used in its construction.” (1979) Connor & Simberloff (1979) Checkerboards • Connor & Simberloff’s (1979) refutation of Diamond (1975) used birds from New Hebrides and West Indies due to unavailability of Diamond’s data • Upon release of data (Mayr & Diamond 2001), Collins, Simberloff & Connor (2011) use “binary matrices” to scan “checkerboard” distributions of birds in the Bismarcks to test Diamond’s assertion of competitive exclusion driving the observed patterns Checkerboards • Collins, Simberloff & Connor (2011) find greater percentage of species/genera exhibiting checkerboard distribution than expected by chance • Result does not refute Diamond’s competitive exclusion hypothesis • Paper does not dismiss competition as an important driver of species distributions, but argues insufficient evidence exists to rule out other hypotheses • So the debate is ongoing Figure from Collins, Simberloff & Connor 2011 Simberloff vs. Diamond cont: SLOSS • From MacArthur & Wilson’s Theory of Biogeography (1963), Diamond (1975b) infers that due to the speciesarea relationship and the importance of habitat connectivity, one large preserve should be preferable to several smaller preserves. Figure from Diamond (1975b) SLOSS • Simberloff & Abele (1976) counter: the Theory of Island Biogeography indeed suggests the superiority of a larger preserve over a smaller preserve all else being equal, but all else is generally not equal and the Theory does not differentiate between 1 large preserve and several small preserves whose combined area equals that of the large SLOSS • Simberloff & Abele (1976) use species-area equation to demonstrate capacity of a number of small reserves to support a greater number of species than a single large • Interestingly, they invoke a competitivelydriven checkerboard-like mechanism as a possible force driving greater species richness in several small preserves! Simberloff vs. Diamond step-by-step Step 1: Diamond makes an assertion with broad implications Step 2: Simberloff & colleagues accuse Diamond of jumping to conclusions Daniel S. Simberloff: Brief Life Summary http://quest.utk.edu/wp-content/uploads/simberloff-3.jpg • Born 1942 • Raised in rural Pennsylvania • Demonstrates early passion for nature, collecting insects from age 5 • Less able to pursue hobby upon move to NYC at 11 http://www.esapubs.org/bulletin/backissues/0874/web_images_oct/awards/eminent_simberloff.jpg Life Summary • Attends Harvard as a math major • Loses excitement over math career and converts to biology; introduced to E.O. Wilson Life Summary • Taken on by Wilson as a grad student • Wilson encourages Simberloff’s application of his math background to ecology • Receives PhD in 1969 • Holds faculty position at Florida State 19681997 • Currently on faculty at University of Kentucky http://media.knoxnews.com/media/img/photos/2012/07/19/752782_t607.JPG Accomplishments • CV: http://www.icbi20 13.org/admin/pers onfile/2013020217 50469987.pdf • 300+ papers published • 70.38 citations per paper (Web of Science) • 109 Book Reviews Back to papers Simberloff & Wilson 1969 http://www.tipsconf.ca/images/Daniel-Simberloff.jpg • First experimental test of Wilson’s equilibrium Theory of Biogeography • D.S. and E.W. fumigate 6 mangrove islands in Florida Keys and observe the returns of arthropod species http://static.guim.co.uk/sys-images/Observer/Pix/pictures/2010/6/2/1275492364008/Dr.-E.O.-Wilson--006.jpg Simberloff & Wilson 1969 • Re-colonization of islands found to conform to Theory • All islands return to original species richness—this suggests the presence of equilibrium • D.S. and E. W. suggest species richness overshoots equilibrium initially, trends downwards (with oscillations) toward equilibrium due to interspecies interaction (i.e. competition/predation) • Existence of equilibrium curves lays foundation for Diamond (1975) Advocacy of Null Models • Many ecological studies had introduced empirically-based models attributing their patterns to such forces as competition (“largely as a legacy of Robert MacArthur”, Simberloff 1978) • Simberloff argued that these explanations had largely not been tested against pure stochasticity (Simberloff 1978) Null models cont. • “Confirmatory evidence per se is not very compelling since one can always find some.” (Simberloff 1983) • Simberloff (1983) argues that community ecology is full of theories that have not been well-tested, and that a “falsification procedure” is needed— i.e., a null hypothesis • “The full range of forces generating the pattern [should] be recognized so that the search for its causes [are] not […] unduly circumscribed initially.” (Simberloff 1983) • Simberloff’s single greatest contribution to community ecology? Simberloff Update http://tntoday.utk.edu/wp-content/uploads/daniel-simberloff-214x300.jpg • Now at University of Tennessee, Simberloff directs the Institute for Biological Invasions • His research spanning roughly the 90’s until now has focused on the ecology of invasive species—some of these studies rank among his most-cited papers Simberloff & Stiling (1996) • Paper questions popular assumption that modern species introductions as biological control methods are sufficiently safe • Mention that most cases have not been studied well enough to say whether introduced species are negatively affecting their new environment • Bring up competition with native species, ecosystem effects and other risks associated with species introductions • Article cited 360+ times Simberloff 2003 • Argues that intensive study of the population biology of invasive organisms is often not necessary, and that the time required to do so can be costly due to continual proliferation of the species • Cites numerous examples of invasive species that were eradicated or controlled using very basic knowledge of the organism’s biology • Emphasizes that early action is often the most effective way to limit damage caused by exotics Simberloff & Gibbons 2004 • “Spontaneous collapse”: when an invasive species’s population abruptly declines without human intervention • Parasites and resource shortages have generally been invoked to explain such declines • But the causes remain speculation in most cases • While a potentially important aspect of invasion ecology, Simberloff & Gibbons do not ascribe great importance to these scenarios in management: spontaneous collapse is not the norm, and the examples contained in the paper comprised a large percentage of those to have been observed References • • • • • • • • • • • • • • Diamond, J. M. 1975. Assembly of species communities. Pages 342-444 in M. L. Cody and J. M. Diamond, editors. Ecology and evolution of communities. Harvard University Press. Cambridge, Massachusetts, USA. Connor, E. F. and Simberloff, D. 1979 The assembly of species communities: chance or competition? Ecology 60:1132-1140. Mayr, E. and Diamond, J. (2001) The birds of northern Melanesia: speciation, ecology, and biogeography. Oxford University Press, Oxford. Collins, M. D., Simberloff, D., and Connor, E. F. 2011. Binary matrices and checkerboard distributions of birds in the Bismarck Archipelago. Journal of Biogeography 38:2373-2383. Diamond, J. M. 1975b. The island dilemma: lessons of modern biogeographic studies for the design of nature preserves. Biological Conservation 7:129-146. Simberloff D. S. and Abele L. G. 1976. Island biogeography theory and conservation practice. Science 191:285-286. Conservation Scholars: Daniel Simberloff. 2008. Web. Accessed 23 April 2014. Simberloff, D. S. 2012. CV. Simberloff, D. S. and Wilson, E.O. 1969. Experimental zoogeography of islands: the colonization of empty islands. Ecology 50:278-296. Simberloff, D. S. 1978. Using island biogeographic distributions to determine if colonization is stochastic. The American Naturalist 112:713-726. Simberloff, D. 1983. Competition theory, hypothesis-testing, and other community ecological buzzwords. The American Naturalist 122:626-635. Simberloff, D. and Stiling, P. 1996. How risky is biological control? Ecology 77:1965-1974. Simberloff, D. 2003. How much information on population biology is needed to manage introduced species? Conservation Biology 17:83-92. Simberloff, D. and Gibbons, L. 2004. Now you see them, now you don’t!-population crashes of established introduced species. Biological Invasions 6:161-172.