1 2 Short Communication 4 Archipelago colonization by ecologically dissimilar amphibians: 5 Evaluating the expectation of common evolutionary history 6 of geographical diffusion in co-distributed rainforest tree frogs 7 in islands of Southeast Asia 8 9 10 Paulette Gonzalez a Q1 , Yong-Chao Su a,b , Cameron D. Siler c , Anthony J. Barley a , Marites B. Sanguila d , 11 Arvin C. Diesmos a,e , Rafe M. Brown a,e,⇑ 12 a Biodiversity Institute and Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045-7561, USA 13 b Department of Biological Science, Tunghai University, Taichung, Taiwan 14 c Sam Noble Museum and Department of Biology, University of Oklahoma, Norman, OK 73073-7029, USA 15 d Father Saturnino Urios University, 8600 Butuan City, Philippines 16 e Herpetology Section, Zoology Division, National Museum of the Philippines, Rizal Park, Padre Burgos Avenue, Manila, Philippines 17 18 19 21 article info 22 Article history: 23 Received 5 July 2013 24 Revised 19 December 2013 25 Accepted 21 December 2013 26 Available online xxxx 27 Keywords: 28 Kurixalus appendiculatus 29 Old World tree frogs Q3 30 Mindanao tree frog 31 Philippines 32 Rhacophorus bimaculatus 33 Frilled Tree Frog 34 Sundaland 35 36 abstract 37 Widespread, co-distributed species with limited relative dispersal abilities represent compelling focal 38 taxa for comparative phylogeography. Forest vertebrates in island archipelagos often exhibit pronounced 39 population structure resulting from limited dispersal abilities or capacity to overcome marine barriers to 40 dispersal. The exceptionally diverse Old World tree frogs of the family Rhacophoridae have colonized the 41 forested island archipelagos of Southeast Asia on multiple occasions, entering the islands of Indonesia 42 and the Philippines via a ‘‘stepping stone’’ mode of dispersal along elongate island chains, separated 43 by a series of marine channels. Here we evaluate the prediction that two tightly co-distributed Philippine 44 rhacophorids colonized the archipelago during concomitant timescales and in the same, linear, ‘‘island- 45 hopping’’ progression. We use a new multilocus dataset, utilize dense genetic sampling from the eastern 46 arc of the Philippines, and we take a model-based phylogeographic approach to examining the two 47 species for similar topological patterns of diversification, genetic structure, and timescales of diversifica- 48 tion. Our results support some common mechanistic predictions (a general south-to-north polarity of col- 49 onization) but not others (timescale for colonization and manner and degree of lineage diversification), 50 suggesting differing biogeographic scenarios of geographical diffusion through the archipelago and 51 unique and idiosyncratic ecological capacities and evolutionary histories of each species. 52 Ó 2013 Elsevier Inc. All rights reserved. 53 54 55 1. Introduction 56 Understanding of the evolutionary and biogeographic processes 57 that have facilitated colonization of island archipelagos is of funda- 58 mental interest to biodiversity specialists focused on the global 59 conservation hotspots of Southeast Asia and the Pacific (Lohman 60 et al., 2011; Brown et al., in press), w Q4 here rates of forest destruction 61 has been higher than anywhere else in the world (Whitmore and 62 Sayer, 1992; Brooks et al., 2002). In the Philippine biodiversity 63 hotspot, high levels of land vertebrate diversity and soaring rates 64 of endemism (Brown and Diesmos, 2009) have fueled the search 65 for common mechanisms of diversification, and piqued biogeogra- 66 phers’ interest in population substructuring, evolutionary parti- 67 tioning, and maintenance of biodiversity (Evans et al., 2003; 68 Esselstyn and Brown, 2009; Oaks et al., 2013; Brown et al., in 69 press). Although the application of molecular data and rigorous 70 statistical tools has greatly enhanced biogeographers’ ability to 71 address questions of diversification in a hypothesis-testing frame- 72 work (Oaks et al., 2013; Brown et al., in press), these efforts have 73 been hampered by a lack of comprehensive biodiversity surveys, 74 logistical obstacles to field work, and a prevailing focus on fine- 75 scale patterns of diversification associated with widespread micro- 76 endemism (Brown and Diesmos, 2009; Brown et al., in press). As a 77 result, biogeographers have only recently begun to identify more 78 widespread, co-distributed groups of species, suitable for hypothe- 79 sis-testing with a multi-taxon approach (Roberts, 2006; Esselstyn 80 et al., 2010; Siler et al., 2010; Q5 Brown et al., 2011; Oaks et al., 2013). 81 One group of amphibians intimately tied to the geographical 82 template as a result of their variable natural history and ecological 1055-7903/$ - see front matter Ó 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ympev.2013.12.006 ⇑ Corresponding author. Address: Biodiversity Institute, 1345 Jayhawk Blvd., Lawrence, KS 66045, USA Q2 . Fax: +1 785 864 3403. E-mail addresses: mbsanguila@urios.edu.ph (M.B. Sanguila), rafe@ku.edu (R.M. Brown). Molecular Phylogenetics and Evolution xxx (2014) xxx–xxx Contents lists available at ScienceDirect Molecular Phylogenetics and Evolution journal homepage: www.elsevier.com/locate/ympev YMPEV 4773 No. of Pages 7, Model 5G 6 January 2014 Please cite this article in press as: Gonzalez, P., et al. Archipelago colonization by ecologically dissimilar amphibians: Evaluating the expectation of com- mon evolutionary history of geographical diffusion in co-distributed rainforest tree frogs in islands of Southeast Asia. Mol. Phylogenet. Evol. (2014), http:// dx.doi.org/10.1016/j.ympev.2013.12.006