Relationships of Floras (& Faunas)Knowledge of earth and organism histories now permit closer examination ofrelationships of disjunct floras and faunas.• Southern Hemisphere temperate• Southern Hemisphere tropics• the Wallace Line• Eastern Asian - Eastern North American temperateThe Wallace LineAlfred Wallace, one of the premier zoobiogeographers, wrote the definitivetreatise “Distributions of Animals” in 1876 where he summarized the knowndistributions and causes of their biogeographical patternsAlfred Wallace’s main interest was in the vertebrate fauna of the Indo-MalayArchipelago from Asia to Australia where he clearly saw a sharp faunistic breakWallace’s tripsSclater’s & Wallace’sfaunistic regionsProbably his mostimportant trip he evermade was a 6 km ferryride from Bali to LombokThe Wallace Line“In the archipelago . . . there are two distinct faunas rigidly circumscribed,which differ as much as those of South America and Africa, and more than thoseof Europe and North America” [Letter to Henry Bates in London (1858)]Sclater’s & Wallace’sfaunistic regionsWallace’s tripsThe Wallace Line“The boundary line often passes between islands closer than others in the samegroup. I believe the western part to be a separated portion of continental Asia,the eastern the fragmentary prolongation of a former Pacific continent”Looking east from Bali across 6 km Lombok Straits“In the archipelago . . . there are two distinct faunas rigidly circumscribed,which differ as much as those of South America and Africa, and more than thoseof Europe and North America” [Letter to Henry Bates in London (1858)]The Wallace LineCover plate from Distributions of AnimalsWallace graphically depicts what has since been termed the “Wallace Line”in his book by showing birds and mammals that are found in the Oriental(Borneo, left) and Australian (New Guinea, right) sidestarsier tree kangarootree shrewtapirloryraquet-tailedkingfisherOriental Fauna Australian FaunaThe Wallace Line• Wallace Line — the imaginary lineseparating the Oriental andAustralian biotas — extends betweenBali and Lombok and betweenBorneo/Philippines and Sulawesi• Several other lines have beenproposed in the region based onparticular groups of animals orplants.• Main issue with most lines is whatdo with Sulawesi (Celebes)The Wallace LineCrested blackmacaqueBear cuscus(marsupial)Backboneof SulawesiSulawesi, with its mixture of Oriental and Australian fauna, was so perplexing toWallace, that he vacillated back and forth on where to place the islandThe Wallace LineThe “Wallace Line” biogeographical riddle was elegantly solved with thecontinental drift theory of Alfred Wegener and the more recent plate tectonicbasis as a mechanism for Earth evolutionEarth and Life Evolve TogetherThe Wallace LineNow know that the two regions are different continental plates that have been movingindependently — the Asian and Australian platesThe IndoMalay - New GuineaArchipelago area includes islandgroups mostly confined to either oftwo continental shelves:Sunda shelf — AsianSahul shelf — AustralianThe Wallace LineCollision of the Australian plate with the Asian plate occurredbetween 15-5 mya40 mya Present10 mya20 myaNote the origins of Bali and Lombok, forming the Wallace LineThe Wallace LineCollision of the Australian plate with the Asian plate occurredbetween 15-5 mya40 mya Present10 mya20 myaSulawesi is a hybrid island from both plates!Note the origins of Bali and Lombok, forming the Wallace LineThe Wallace LineWallace Line Revisited — Plate tectonics, rafting in isolation, and recentcontact of Australian and Oriental biota: 55 million year storyThe Wallace LineTree shrews (family Tupaiidae) were indicated byWallace as honoring this biogeographical line. AnAsian group whose entire range gets as far east as Baliand Borneo but not to Lombok or SulawesiTree shrew family & individualspecies distributionsThe Wallace LineBorneo dipterocarpDistribution of generaof DipterocarpaceaeAll but 3 of the genera of Dipterocarpaceae honorthe Wallace LineSurprising considering thewinged fruit in the family isdesigned for dispersalThe Wallace LineDo plants honor the Wallace Line?A Biogeographical and Phylogenetic Analysis of Dipterocarpaceae: Do They Honor the Wallace Line?Amelia Krug and Kenneth SytsmaUniversity Of Wisconsin, Department Of Botany [email protected], [email protected] Materials and MethodsResults and DiscussionThe family Dipterocarpaceae (Malvales) is divided into three subfamilies (Dipterocarpoideae,Monotoideae, and Pakaraimoideae) and ispantropical in distribution. Dipterocarpoideaeconsists of 13 genera and about 475 species, most ofwhich are large trees dominant in the emergentcanopy of lowland everwet rain forests in India andSri Lanka to West Malaysia (Kajita et al., 1998;Fig.1). The geographic distribution of the majority ofthese species correlates directly with thebiogeographic boundary of the Wallace Line;however, some genera including Anisoptera, Hopea,Vatica, Shorea, and Dipterocarpus have crossed eastover the boundary of the line (Whitmore 1981; Fig.2). The goal of this study is to infer whether thesespecies crossed over the Wallace Line subsequent tothe collision of the Sunda and Sahul Plates 5-10 Ma,or, earlier and over greater oceanic distances.Taxon Sampling: The cpDNA sequences(trnL Intron and trnL-trnF IntergenicSpacer) of 71 species from the subfamilyDipterocarpoideae, 1 species from thesubfamily Monotoideae, and 3 outgroupspecies were gathered from GenBank andaligned within MacClade 4.08 OX S. Analysis: Divergence times were estimatedwithin BEAST v1.7.2 using fossil dates anddivergence estimates of Dipterocarpus(Meijer 1974), Diptercarpoideae (Dutta et al.2011), Dipterocarpaceae (Appanah et al.1998), and Malvales (Wikstrom et al. 2001)obtained from prior studies. Previousanalyzation included using PAUP MaximumParsimony and Maximum Likelihood asbeginning phylogenetic estimates.Figure 2. Dipterocarp Distribution (with Wallace Line added) - Whitmore, 1981.Figure 1. Dipterocarp Habit (Blomqvist) and Fruit (Rodd ) Figure 3. Phylogram of Dipterocarpaceae as inferred from BEAST analysis of cpDNA data showing mean divergence time estimates with 95% highest posterior density(HPD) intervals (blue bars). Arabidopsis thaliana, Tilia kiusiana, and Cistus ladanifer were used an outgroup.With four fossil calibrations (Malvales, Dipterocarpaceae, Dipterocarpoideae, and