Phylogeography and Genetic Ancestry of Tigers (Panthera tigris)

Abstract

Eight traditional subspecies of tiger (Panthera tigris), of which three recently became extinct, are commonly recognized on the basis of geographic isolation and morphological characteristics. To investigate the species' evolutionary history and to establish objective methods for subspecies recognition, voucher specimens of blood, skin, hair, and/or skin biopsies from 134 tigers with verified geographic origins or heritage across the whole distribution range were examined for three molecular markers: (1) 4.0 kb of mitochondrial DNA (mtDNA) sequence; (2) allele variation in the nuclear major histocompatibility complex class II DRB gene; and (3) composite nuclear microsatellite genotypes based on 30 loci. Relatively low genetic variation with mtDNA, DRB, and microsatellite loci was found, but significant population subdivision was nonetheless apparent among five living subspecies. In addition, a distinct partition of the Indochinese subspecies P. t. corbetti into northern Indochinese and Malayan Peninsula populations was discovered. Population genetic structure would suggest recognition of six taxonomic units or subspecies: (1) Amur tiger P. t. altaica; (2) northern Indochinese tiger P. t. corbetti; (3) South China tiger P. t. amoyensis; (4) Malayan tiger P. t. jacksoni, named for the tiger conservationist Peter Jackson; (5) Sumatran tiger P. t. sumatrae; and (6) Bengal tiger P. t. tigris. The proposed South China tiger lineage is tentative due to limited sampling. The age of the most recent common ancestor for tiger mtDNA was estimated to be 72,000–108,000 y, relatively younger than some other Panthera species. A combination of population expansions, reduced gene flow, and genetic drift following the last genetic diminution, and the recent anthropogenic range contraction, have led to the distinct genetic partitions. These results provide an explicit basis for subspecies recognition and will lead to the improved management and conservation of these recently isolated but distinct geographic populations of tigers.

Mitochondrial DNA variation in the malaria vector Anopheles minimus across China, Thailand and Vietnam: evolutionary hypothesis, population structure and population history

“…The divergence of Lineages A and B, which dates to B1 mya using the conventional calibration rate for animal mtDNA of 2% divergence per million years (Powell et al, 1986), has likely accumulated over multiple glacial cycles. Our findings therefore concur with largerscale phylogeographic studies on tigers (Luo et al, 2004), dholes (Iyengar et al, 2005) and elephants (Fleischer et al, 2001) that Pleistocene climatic change has played a major role in shaping the genetic diversity of the mainland Southeast Asian biota. The different distributions of the two lineages suggest isolation in allopatric eastern and western forest refugia.…”

Mitogenomics of the Extinct Cave Lion, Panthera spelaea (Goldfuss, 1810), Resolve its Position within the Panthera Cats

“…Comparison with other recent pantherines (Figure 3) demonstrates that the degree of mitochondrial divergence is considerably greater than that found between well-defined subspecies in modern lion (P. leo) , leopard (P. pardus) (Uphyrkina et al, 2001), or tiger (P. tigris) (Luo et al, 2004). The estimated divergence time between P. leo and P. spelaea is also greater than that between the two newly recognised species of clouded leopard, Neofelis nebulosa and N. diardi, which has been estimated at 1.…”

Evolutionary analysis of a large mtDNA translocation (numt) into the nuclear genome of the Panthera genus species

“…The full sequence for both tiger cymt and numt is presented here, providing a valuable contribution for research in felids. Such data has greatly facilitated the validation of the matrilineal genealogy of current tiger subspecies (Luo et al, 2004) and certainly will be highly useful for research on the other closely related Panthera species. Refined accurate population genetic inferences will represent an effective contribution for the conservation and the management of these endangered cat species.…”