Skip to main content
Dryad

Diversifying in the mountains: spatio-temporal diversification of frogs in the Western Ghats biodiversity hotspot

Cyriac, Vivek1; Mohan, Ashwini2; Dinesh, K. P.3; Torsekar, Varun1; Jayarajan, Aditi4; Swamy, Priyanka1; Vijayakumar, S. P.1; Shanker, Kartik1

Published Jan 19, 2024 on Dryad. https://doi.org/10.5061/dryad.8kprr4xv4

Data files

Jan 19, 2024 version files 6.51 MB

Abstract

Mountain ranges are hotspots of biodiversity. However, the mechanisms that generate biodiversity patterns in different mountainous regions and taxa are not apparent. The Western Ghats (WG) escarpment in India is a globally recognised biodiversity hotspot with high species richness and endemism. Most studies have either invoked paleoclimatic conditions or climatic stability in the southern WG refugium to explain this high diversity and endemism. However, the factors driving macroevolutionary change remain unexplored for most taxa. Here, we generated the most comprehensive dated phylogeny to date for ranoid frogs in the WG and tested the role of paleoclimatic events or climatic stability in influencing frog diversification. We found that the diversity of different ranoid frog clades in the WG either accumulated at a constant rate through time or underwent a decrease in speciation rates around 3–2.5 Ma during the Pleistocene glaciation cycles. We also find no significant difference in diversification rate estimates across elevational gradients and the three broad biogeographic zones in the WG (northern, central, and southern WG). However, time-for-speciation explained regional species richness within clades, wherein older lineages have more extant species diversity. Overall, we find that global paleoclimatic events have had little impact on WG frog diversification throughout most of its early history until the Quaternary and that the WG may have been climatically stable allowing lineages to accumulate and persist over evolutionary time.