Genetic variation and differentiation in Indirana beddomii frogs endemic to the Western Ghats biodiversity hotspot

Nair, Abhilash; Gopalan, Sujith V.; George, Sanil; Kumar, K. Santhosh; Shikano, Takahito; Merilä, Juha

doi:10.1007/s10592-012-0389-z

Cited by 14 publications

(10 citation statements)

References 43 publications

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“…This gap is also a known biogeographic divide causing genetic differentiation across various taxa including frogs (Nair et al . ) and some plants (Bahulikar et al . ), but not in macaques (Chakraborty ) or centipedes (Joshi & Karanth ).…”

Section: Discussionmentioning

confidence: 99%

Islands within islands: two montane palaeo‐endemic birds impacted by recent anthropogenic fragmentation

et al. 2015

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Anthropogenic habitat fragmentation of species that live in naturally patchy metapopulations such as mountaintops or sky islands experiences two levels of patchiness. Effects of such multilevel patchiness on species have rarely been examined. Metapopulation theory suggests that patchy habitats could have varied impacts on persistence, dependent on differential migration. It is not known whether montane endemic species, evolutionarily adapted to natural patchiness, are able to disperse between anthropogenic fragments at similar spatial scales as natural patches. We investigated historic and contemporary gene flow between natural and anthropogenic patches across the distribution range of a Western Ghats sky-island-endemic bird species complex. Data from 14 microsatellites for 218 individuals detected major genetic structuring by deep valleys, including one hitherto undescribed barrier. As expected, we found strong effects of historic genetic differentiation across natural patches, but not across anthropogenic fragments. Contrastingly, contemporary differentiation (D(PS)) was higher relative to historic differentiation (F(ST)) in anthropogenic fragments, despite the species' ability to historically traverse shallow valleys. Simulations of recent isolation resulted in high D(PS)/F(ST) values, confirming recent isolation in Western Ghats anthropogenic fragments and also suggesting that this ratio can be used to identifying recent fragmentation in the context of historic connectedness. We suggest that in this landscape, in addition to natural patchiness affecting population connectivity, anthropogenic fragmentation additionally impacts connectivity, making anthropogenic fragments akin to islands within natural islands of montane habitat, a pattern that may be recovered in other sky-island systems.

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Section: Discussionmentioning

confidence: 99%

Islands within islands: two montane palaeo‐endemic birds impacted by recent anthropogenic fragmentation

et al. 2015

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“…We suggest that the relatively greater impact of the Palghat Gap may be owing to it being a wider (40 km wide compared with 10 km Shenkottah and 2-3 km wide Chaliyar valley) and deeper gap than the other two. Although no systematic studies have been conducted comparing species of differing ecologies and dispersal abilities, an impact of this Gap has also been found in small, restricted species like frogs [33] and some plants [34] and even in large-bodied, wide-ranging species like elephants [35]. However, certain older taxa like centipedes [36] and some long-lived trees [37] do not appear to be affected by this Gap.…”

Section: (A) Nested Patterns Of Divergences In Time and Spacementioning

confidence: 99%

Deep and wide valleys drive nested phylogeographic patterns across a montane bird community

et al. 2015

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Montane species distributions interrupted by valleys can lead to range fragmentation, differentiation and ultimately speciation. Paleoclimatic fluctuations may accentuate or reduce such diversification by temporally altering the extent of montane habitat and may affect species differentially. We examined how an entire montane bird community of the Western Ghats-a linear, coastal tropical mountain range-responds to topographic valleys that host different habitats. Using genetic data from 23 species (356 individuals) collected across nine locations, we examined if different species in the community reveal spatial concordance in population differentiation, and whether the timing of these divergences correlate with climatic events. Our results reveal a nested effect of valleys, with several species (10 of 23) demonstrating the oldest divergences associated with the widest and deepest valley in the mountain range, the Palghat Gap. Further, a subset of these 10 species revealed younger divergences across shallower, narrower valleys. We recovered discordant divergence times for all valley-affected montane birds, mostly in the Pleistocene, supporting the Pliestocene-pump hypotheses and highlighting the role of climatic fluctuations during this period in driving species evolution. A majority of species remain unaffected by valleys, perhaps owing to geneflow or extinction-recolonization dynamics. Studying almost the entire community allowed us to uncover a range of species' responses, including some generalizable and other unpredicted patterns.

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“…), and frogs (Nair et al. ). Other than that, very little is known on the impact of the topography of the Western Ghats on genetic structure, especially in plants, and it is not known whether these gaps could be considered as boundaries for conservation units of plant species.…”

Section: Introductionmentioning

confidence: 99%

Genetic structure and demographic history of the endangered tree species Dysoxylum malabaricum (Meliaceae) in Western Ghats, India: implications for conservation in a biodiversity hotspot

Bodare

Tsuda

Ravikanth

et al. 2013

Ecology and Evolution

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The impact of fragmentation by human activities on genetic diversity of forest trees is an important concern in forest conservation, especially in tropical forests. Dysoxylum malabaricum (white cedar) is an economically important tree species, endemic to the Western Ghats, India, one of the world's eight most important biodiversity hotspots. As D. malabaricum is under pressure of disturbance and fragmentation together with overharvesting, conservation efforts are required in this species. In this study, range-wide genetic structure of twelve D. malabaricum populations was evaluated to assess the impact of human activities on genetic diversity and infer the species’ evolutionary history, using both nuclear and chloroplast (cp) DNA simple sequence repeats (SSR). As genetic diversity and population structure did not differ among seedling, juvenile and adult age classes, reproductive success among the old-growth trees and long distance seed dispersal by hornbills were suggested to contribute to maintain genetic diversity. The fixation index (FIS) was significantly correlated with latitude, with a higher level of inbreeding in the northern populations, possibly reflecting a more severe ecosystem disturbance in those populations. Both nuclear and cpSSRs revealed northern and southern genetic groups with some discordance of their distributions; however, they did not correlate with any of the two geographic gaps known as genetic barriers to animals. Approximate Bayesian computation-based inference from nuclear SSRs suggested that population divergence occurred before the last glacial maximum. Finally we discussed the implications of these results, in particular the presence of a clear pattern of historical genetic subdivision, on conservation policies.

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Genetic variation and differentiation in Indirana beddomii frogs endemic to the Western Ghats biodiversity hotspot

Cited by 14 publications

References 43 publications

Islands within islands: two montane palaeo‐endemic birds impacted by recent anthropogenic fragmentation

Islands within islands: two montane palaeo‐endemic birds impacted by recent anthropogenic fragmentation

Deep and wide valleys drive nested phylogeographic patterns across a montane bird community

Genetic structure and demographic history of the endangered tree species Dysoxylum malabaricum (Meliaceae) in Western Ghats, India: implications for conservation in a biodiversity hotspot

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