Abstract booklet - gtö – Society for Tropical Ecology

122 PARALLEL SESSION HALL H III | HOTSPOT WALLACEAPARALLEL SESSION HALL H III | HOTSPOT WALLACEA123HOTSPOT SULAWESI: TARSIER DIVERSITY MIRRORS WALLACEA’STROUBLED PASTTHE BIOGEOGRAPHY OF SULAWESI - IS THERE EVIDENCE FOR AVICARIANT ORIGIN OF TAXA ON THE ISLAND?Stefan Merker 1 , Christine Driller 2 , Dyah Perwitasari-Farajallah 3 , JokoPamungkas 3 , Wirdateti 4 , Bruno Streit 1Björn Stelbrink 1 , Matthias Glaubrecht 1 , Thomas von Rintelen 11Museum f. Naturkunde Berlin, Berlin, DE, bjoern.stelbrink@mfn-berlin.deTHURSDAY 10:00 Hall H III1Goethe University Frankfurt, Frankfurt am Main, DE, smerker@bio.uni-frankfurt.de, 2 Johannes-Gutenberg University Mainz, Mainz, DE, 3 Primate Research Center,Bogor Agricultural University, Bogor, ID, 4 Research Center for Biology - LIPI,Cibinong, IDDue to its location in the transition zone between Asia and Oceania, to itseffective isolation from major landmasses, and to a troubled geologic history,the Indonesian island of Sulawesi hosts a high diversity of endemic vertebrates.Among these are tarsiers, very small nocturnal primates of an ancientevolutionary lineage. Here, we evaluate likely effects of microplate tectonicshifts and sea level fluctuations on the allopatric diversification of Tarsius in theWallacea region. Our presentation covers multibiological evidence of Sulawesi’shigh tarsier diversity, a detailed analysis of an interspecific hybrid zone, and ourthoughts on the geological and biological processes underlying these patterns.Most tarsier ranges roughly concur with areas of endemism as identified forother taxa. There are, however, notable exceptions challenging our current viewof primate dispersal across the region. One of these concerns Wallace’s tarsier,a recently discovered species occupying a disjunct range in Central Sulawesi.Morphological and bioacoustic traits as well as mitochondrial, Y-chromosomal,and microsatellite DNA patterns clearly separate the new taxon from all othertarsiers. The two isolated populations slightly differ from each other in bodysize and duet call characteristics but share an ancestral mtDNA polymorphismpredating population segregation. Owing to the new species’ distributionacross a geographic bottleneck (the Isthmus of Palu), it plays a key role in ourquest to understand tarsier dispersal across the island. Thus, based on theevidence uniting as well as untying the two populations, we discuss reasonsand timing of their divergence in the light of climatic history.Sulawesi is the largest island of the Wallacea, an area of oceanic islands betweenthe continental Sunda and Sahul shelves. The non-marine fauna of Sulawesiis highly endemic and contains some apparently ancient elements such asthe Babirusa. Dispersal, e.g. across Makassar Strait, is now widely accepted asaccounting for the origin of most of Sulawesi’s animals. Vicariance scenarioscannot be a priori excluded, though. The complex geologic history of the island,which has been connected to Borneo in the Eocene and is a tectonic compositecomprising also terranes from the Australian margin, offers a theoretical chancefor a vicariant origin of Sulawesi’s taxa both from west and east. While the riseof molecular phylogenetics during the last two decades has helped to clarifythe relationships of taxa from Sulawesi, the timing of diversification events ismore difficult and can be crucial with respect to discussing dispersal versusvicariance hypotheses.Recent biogeographic studies containing or allowing divergence time estimatesof Sulawesi taxa are reviewed here with respect to the Island’s geology. It issuggested that there is as yet little reliable evidence for a vicariant origin of taxaon Sulawesi from the west. Molecular phylogenetic data from two freshwatergastropod groups with poor dispersal capabilities suggest a potential vicariantorigin of these snails via terrane rafting from the Australian margin, though.Tectonic events, i.e. the separation of candidate terranes from the Australianmargin and their collision with Sulawesi, provide the temporal bounds fortesting this hypothesis, which is attempted with a molecular clock approach.The past distribution of land and sea, particularly for small continentalfragments, is a crucial issue debated among biogeographers and geologists,and well-supported biological data can make a contribution here.Phylogeographic patterns within Sulawesi are used as an additional line ofevidence for identifying potential candidate terranes. In at least one snailgroup, the correlation of phylogeographic subdivisions with tectonic provincessuggests that not only the colonization of Sulawesi, but also subsequentdiversification events on the island have been greatly influenced by geologicevents. The respective gastropod data are contrasted with patterns derivedfrom the study of vertebrates and insects.THURSDAY 10:15 Hall H IIIgtöSociety for Tropical Ecology | Gesellschaft für Tropenökologie e.V. Status and future of tropical biodiversity | Frankfurt, 21 - 24 February 2011gtö