1Species and Areas: History of IdeasHow do you choose between dispersalist and vicariance models?1. Acceptance of plate tectonicsUp until the 1960s, most persons considered theearth's crust to be fixed. Finally, in the 1960s thegeological evidence was at hand that madecontinental drift irrefutable.Two important scientific advances in the mid 20th century haverevolutionized historical biogeography2. Development of new phylogenetic methodsWilli Hennig (1950) introduced the modernconcepts of phylogenetic theory (first published in1956). Using this methodology, hypotheses ofhistorical lineages of species could bereconstructed.The affinities of all the beings of the same class havesometimes been represented by a great tree . . . Asbuds give rise by growth to fresh buds, and these ifvigorous, branch out and overtop on all sides many afeebler branch, so by generation I believe it has beenwith the great Tree of Life, which fills with its deadand broken branches the crust of the earth, and covers thesurface with its ever branching and beautiful ramifications.“Phylogenetics”Charles Darwin, 1859PhylogeneticsBuilding “trees” - showing how “branches” or “clades” areconnected to each otherPhylogeneticsBut . . . We only have extant species - the “leaves”? - and so we must estimate how the “branches” onceconnected the “leaves”2Phylogenetics: TimeThus . . . Phylogenetics is the estimation of the “tree”through “time” knowing only the “leaves”Phylogenetics: Time & SpaceHowever, the “leaves” are scattered over “space”. Some areashave related “leaves”, others have unrelated “leaves”. Thus,phylogenetics is compounded by issues of both “time” and“space”.Phylogenetics: Time & Space & FormAdditionally, many related “leaves” appear quite divergent in “form”,while other unrelated “leaves” converge in “form”. Thus,phylogenetics is compounded by issues of “time” and “space” and“form”.“Earth and Life Evolve Together”Leon Croizat (1964)Panbiogeography(Space, time, form: the biological synthesis)One of the first articulations of this synthesis is by the founder of“panbiogeography” . . .3PhylogeneticsBefore linking biogeography with phylogenetics, we need to take acloser look at how to estimate the “tree”Willi Hennig (entomologist) and WalterZimmerman (botanist) developed formalmethods for reconstructing phylogeniesHennig’s book “PhylogeneticSystematics” was translated into Englishand introduced the method ofphylogenetics called cladisticsPhylogeneticsHennigPhylogeneticsHow are these 6 species of genus Oppositifolia related?Cladistics forms groups based on shared-derived characters or synapomorphiesAre the blue flowers derived (apomorph) orare they primitive (plesiomorph)?PhylogeneticsHow are these 6 species of genus Oppositifolia related?Cladistics forms groups based on shared-derived characters or synapomorphiesAre the blue flowers derived (apomorph) orare they primitive (plesiomorph)?Use the genus Alternifolia asan outgroup to polarize thecharacters in the ingroup4PhylogeneticsWhat if convergences or reversals have taken place inevolution?Phylogenetics1. Belongs with other alternateleaved species; but blue flowershave evolved twice independentlyWhat if convergences or reversals have taken place inevolution?Phylogenetics2. Belongs with other blueflowered species; but reversalback to alternate leaves hasoccurredWhat if convergences or reversals have taken place inevolution?PhylogeneticsWhat if convergences or reversals have taken place inevolution?Both of these phylogenetic trees are equally likely based on parsimony —they both require one extra stepMaximum parsimony, maximum likelihood, etc. used as optimality criteria inphylogenetics to choose which of potentially many different trees is best5PhylogeneticsCladistics strives to recognize or classifygroups that are monophyletic — includesall descendants of one ancestorvs. polyphyletic groups — with more than oneancestorvs. paraphyletic groups — with one ancestor,but some descendants are not includedPhylogeneticsThe Bryophytes appear here asa paraphyletic groupCladistics strives to recognize or classifygroups that are monophyletic — includesall descendants of one ancestorCommon ancestor“If philosophy is the devil’s whore, asMartin Luther once quipped, thenbiogeography and biologicalsystematics are fast becoming OldNick’s bordello” (Craw, 1988b)PhylogeneticsPhylogenetics and historical biogeographyare now intimately intertwined . . .But before looking at how cladistics andbiogeography were put together in the 1960sand 1970s, we have to look atpanbiogeography a decade earlierPanbiogeographyLeon Croizat(1894-1982)In his book “Panbiogeography”,attempts to synthesize “space,”“time,” and “form” — used themetaphor “Earth and LifeEvolve Together”“An introductory synthesis ofphytogeography, zoogeography,and geology” — title page6PanbiogeographyIn his book “Panbiogeography”,attempts to synthesize “space,”“time,” and “form” — used themetaphor “Earth and LifeEvolve Together”“An introductory synthesis ofphytogeography, zoogeography,and geology” — title pageAlthough now largely dismissed, Panbiogeography is consideredthe forerunner of modern historical biogeography methods;recent advocates include Robin Craw• Distributions plotted on maps, andconnected by lines• Individual / Generalized tracks• Baselines• Main massings• Intersection nodes• No phylogeny! - comparison ofdifferent groups (history of “biotas”)PanbiogeographyPanbiogeographyIndividual track — a line thatminimizes the distance connectingall localities (minimal spanningtree)Lepechinia hastataHawaiiPanbiogeographyBryan Drew,422 TA, andLepechinia expertCroizat’s very first figure of a track (fig. 3)is Lepechinia (Lamiaceae - mints) showingdisjuncts with Hawaii and Mascarenes7PanbiogeographyBaseline — a track orientated in terms of the sea or ocean basinsthat the track crosses or circumscribesPanbiogeographyBaseline — a track orientated in terms of the sea or ocean basinsthat the track crosses or circumscribesAegotheles albertisi Mountain owletPanbiogeographyMain massing — a numerical, genetical,or morphological center of diversity for aparticular taxon or group of taxa (allowsorientation of track)Main massing of Aegotheles (and extinctMegaegotheles), track, and its