Human‐mediated introduction of introgressed deer across Wallace's line: Historical biogeography of Rusa unicolor and R. timorensis

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.

Widespread hybridization in the introduced hog deer population of Victoria, Australia, and its implications for conservation

“…The second consideration when evaluating the Victorian hog deer population for translocations is the possibility that either past or contemporary hybridization has occurred. Hybridization is prolific within the family Cervidae, and hybrid zones have been recorded in the genera Cervus (Lowe & Gardiner, 1975;McDevitt et al, 2009;Moore & Littlejohn, 1989;Senn & Pemberton, 2009), Odocoileus (Ballinger, Blankenship, Bickham, & Carr, 1992;Carr, Ballinger, Derr, Blankenship, & Bickham, 1986;Cathey, Bickham, & Patton, 1998), and most recently in Rusa (Martins, Schmidt, Lenz, Wilting, & Fickel, 2018). While hybridization between species within the Axis genus has not been reported in the wild, there have been cases of chital (Axis axis) and hog deer hybrid offspring being born in captivity, with animals from the two species needing to be separated due to their proclivity to interbreed (Gray, 1972;Mayze & Moore, 1990;McMaster, 1871).…”

Multiplex PCRs for the specific identification of marsupial and deer species from faecal samples as a basis for non-invasive epidemiological studies of parasites

“…The cytb gene sequence derived from a sambar deer from O'Shannassy, Victoria (accession no. MN746795) was identical to those representing Sri Lankan subclade B (GenBank: MF176994, MF177001 and MF177018; [30]); the cytb gene sequence derived from a red deer from Yan Yean, Victoria (accession no. MN746793) was identical to that of the Western and Central European red deer clade (GenBank: KX496937 and MF872247; [38,39]); cytb gene sequence derived from a fallow deer from Cardinia, Victoria (accession no.…”

“…To overcome this problem, we have developed multiplex PCRs to authenticate the origin of individual faecal samples from these animal species utilising genetic markers in mitochondrial (mt)DNA. We focused on using markers within the mitochondrial cytochrome b (cytb) gene, because (i) mt gene sequence (including cytb) data sets were publicly available for the six target animal species [26][27][28][29][30] and because the abundance of mtDNA in cells/samples would allow the development of assays with high analytical sensitivity.…”

Mitogenome Phylogeny Including Data from Additional Subspecies Provides New Insights into the Historical Biogeography of the Eurasian lynx Lynx lynx

“…In order to obtain a more complete understanding of the evolutionary history of such wide-ranging species, data from small, isolated populations, including those at range margins, must be considered in phylogeographic studies (tiger: [8], Himalayan wolf: [9]; Himalayan brown bear: [10]). Such small or edge populations may harbour important components of a species' total genetic diversity (clouded leopard: [11,12]; Himalayan brown bear: [10]; Java sambar: [13]), particularly if refugial populations of former glacial periods have not substantially increased their range (Brown bear in the Caucasus: [14]; Brown bear in the Himalayas: [10]; Eurasian lynx in the Caucasus: [15]). Among wild felids, the Eurasian lynx Lynx lynx has the widest distribution in the Palearctic.…”