Research interests

The fascinating journey of the Indian subcontinent in the last hundred million years, from the Gondwana towards the Eurasia, is marked with several geoclimatic events. The Indian subcontinent not only hosts relic lineages from the Gondwana but also the migrants from other landmasses it encountered during the journey. While the canonical theories of continental drift provide information on large scale distribution patterns and biogeography of organisms on the Indian subcontinent, multigene molecular phylogenies and molecular dating are providing a much finer picture of how various cladogenetic evens such as speciation, dispersal, vicariance and extinction might have shaped its exceptional biological diversity. This is especially true for lower vertebrates, or Anamniotes like freshwater fishes, which have narrow niches and limited dispersal capacities. Our large scale molecular phylogenetic studies of freshwater fishes have revealed that the journey of Indian subcontinent was much more eventful than previously thought and requires proposing and testing multiple alternate hypothesis to understand the original of diversification of India freshwater fishes. Our work on reconstructing ancestral states in phylogenies based on two and a half decades of ichthyological explorations in the Peninsular India. These explorations have not only led to discoveries of multiple endemic taxa and adaptive radiations, but have also unveiled how tectonic activities, geological events, ancient river captures and paleoclimate have shaped biological evolution on the Indian subcontinent. Although our work is focused mainly on fishes, we also explore other taxa, including other Anamniotes like amphibians. 

Organisms that live in extreme environments, like rapid torrential streams or subterranean aquifers, exhibit interesting behavioural, morphological, anatomical and physiological adaptations to cope up with their environmental conditions. How natural selection affects the genes and their expression to cope up with the environmental stress can provide interesting insights on the gene function and regulation. We study the molecular selection acting on genes and regulatory regions of whole nuclear and mitochondrial genomes to understand the genomic basis of evolutionary adaptations. The study has provided novel insights into how intensification and relaxation of selection of protein coding genes, which has implications in both our understanding of basic evolutionary mechanisms and conservation of threatened taxa.

Selfish genetic elements, like transposons or the jumping genes, utilize host resources for increasing their copy number in the genomes. Their ability to jump from one genomic locus to another make them a threat to the genomic integrity in addition to being a metabolic burden for the host. As a result, host has evolved regulatory mechanisms to keeps the copy number of transposons in control. The host-transposon conflict has resulted in fascinating dynamics that can be captured in the variety of transposon strategies and host regularoty mechanisms in different organisms. We use evolutionary game theory and multilevel selection approaches to model the conflict between host transposon interactions to predict the evolution of various alternate strategies and use bioinformatic tools to test the predictions in available genomics data in GenBank database.