Human‐mediated introduction of introgressed deer across Wallace's line: Historical biogeography of Rusa unicolor and R. timorensis. Issue 3 (27th December 2017)

• Record Type: Journal Article
• Authors: Martins, Renata F.; Schmidt, Anke; Lenz, Dorina; Wilting, Andreas; Fickel, Joerns
• Is Part Of: Ecology and evolution. Volume 8:Issue 3(2018)
• Page Start: 1465
• Page End: 1479
• Publication Date: 2017-12-27
• Subjects: Cervidae -- human introduction -- hybridization -- Phylogeography -- Sundaland -- Wallace's line; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.3754
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: In this study we compared the phylogeographic patterns of two Rusa species, Rusa unicolor and Rusa timorensis, in order to understand what drove and maintained differentiation between these two geographically and genetically close species and investigated the route of introduction of individuals to the islands outside of the Sunda Shelf. We analyzed full mitogenomes from 56 archival samples from the distribution areas of the two species and 18 microsatellite loci in a subset of 16 individuals to generate the phylogeographic patterns of both species. Bayesian inference with fossil calibration was used to estimate the age of each species and major divergence events. Our results indicated that the split between the two species took place during the Pleistocene, ~1.8 Mya, possibly driven by adaptations of R. timorensis to the drier climate found on Java compared to the other islands of Sundaland. Although both markers identified two well‐differentiated clades, there was a largely discrepant pattern between mitochondrial and nuclear markers. While nDNA separated the individuals into the two species, largely in agreement with their museum label, mtDNA revealed that all R. timorensis sampled to the east of the Sunda shelf carried haplotypes from R. unicolor and one Rusa unicolor from South Sumatra carried a R. timorensis haplotype. Our results show that hybridization occurred between these two sister species in Sundaland during the Late Pleistocene and resulted in human‐mediated introduction of hybrid descendants in all islands outside Sundaland. Abstract : This study investigated the historical biogeography of two Rusa deer species distributed throughout Southeast Asia. Our results showed that despite a clear species split, possible due to dry climate adaptations of the Javan deer in Java, the two species have hybridized during the Late Pleistocene. More importantly, our results showed that all individuals introduced by humans to the islands of Moluccas, Timor, and Sulawesi were of hybrid descent. These results may have important taxonomic and conservation implications.