title: Sex-biased dispersal and volcanic activities shaped phylogeographic patterns of extant Orangutans (genus: Pongo).
abstract: The Southeast Asian Sunda archipelago harbors a rich biodiversity with a substantial proportion of endemic species. The evolutionary history of these species has been drastically influenced by environmental forces, such as fluctuating sea levels, climatic changes, and severe volcanic activities. Orangutans (genus: Pongo), the only Asian great apes, are well suited to study the relative impact of these forces due to their well-documented behavioral ecology, strict habitat requirements, and exceptionally slow life history. We investigated the phylogeographic patterns and evolutionary history of orangutans in the light of the complex geological and climatic history of the Sunda archipelago. Our study is based on the most extensive genetic sampling to date, covering the entire range of extant orangutan populations. Using data from three mitochondrial DNA (mtDNA) genes from 112 wild orangutans, we show that Sumatran orangutans, Pongo abelii, are paraphyletic with respect to Bornean orangutans (P. pygmaeus), the only other currently recognized species within this genus. The deepest split in the mtDNA phylogeny of orangutans occurs across the Toba caldera in northern Sumatra and, not as expected, between both islands. Until the recent past, the Toba region has experienced extensive volcanic activity, which has shaped the current phylogeographic patterns. Like their Bornean counterparts, Sumatran orangutans exhibit a strong, yet previously undocumented structuring into four geographical clusters. However, with 3.50 Ma, the Sumatran haplotypes have a much older coalescence than their Bornean counterparts (178 kya). In sharp contrast to the mtDNA data, 18 Y-chromosomal polymorphisms show a much more recent coalescence within Sumatra compared with Borneo. Moreover, the deep geographic structure evident in mtDNA is not reflected in the male population history, strongly suggesting male-biased dispersal. We conclude that volcanic activities have played an important role in the evolutionary history of orangutans and potentially of many other forest-dwelling Sundaland species. Furthermore, we demonstrate that a strong sex bias in dispersal can lead to conflicting patterns in uniparentally inherited markers even at a genus-wide scale, highlighting the need for a combined usage of maternally and paternally inherited marker systems in phylogenetic studies.
authors.affiliation: Anthropological Institute & Museum, University of Zurich, Zurich, Switzerland. a.nater@aim.uzh.ch
authors.forename: Alexander
authors.initials: A
authors.lastname: Nater
authors.forename: Pirmin
authors.initials: P
authors.lastname: Nietlisbach
authors.forename: Natasha
authors.initials: N
authors.lastname: Arora
authors.forename: Carel P
authors.initials: CP
authors.lastname: van Schaik
authors.forename: Maria A
authors.initials: MA
authors.lastname: van Noordwijk
authors.forename: Erik P
authors.initials: EP
authors.lastname: Willems
authors.forename: Ian
authors.initials: I
authors.lastname: Singleton
authors.forename: Serge A
authors.initials: SA
authors.lastname: Wich
authors.forename: Benoit
authors.initials: B
authors.lastname: Goossens
authors.forename: Kristin S
authors.initials: KS
authors.lastname: Warren
authors.forename: Ernst J
authors.initials: EJ
authors.lastname: Verschoor
authors.forename: Dyah
authors.initials: D
authors.lastname: Perwitasari-Farajallah
authors.forename: Joko
authors.initials: J
authors.lastname: Pamungkas
authors.forename: Michael
authors.initials: M
authors.lastname: Krützen
mesh_terms: D000818:Animals; D004272:DNA, Mitochondrial / Q000235:genetics; D005260:Female; D005819:Genetic Markers / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics; D006239:Haplotypes; D008297:Male; D010802:Phylogeny; D058974:Phylogeography; D011148:Pongo pygmaeus / Q000145:classification / Q000235:genetics*; D012737:Sex Factors; D014998:Y Chromosome / Q000235:genetics
chemical_list: D004272:DNA, Mitochondrial; D005819:Genetic Markers