Thesis Defense at CES on 14 June 2019 at 3:00 pm titled "Biogeography and comparative phylogeography of freshwater snails of India" by Maitreya Sil from CES, IISc
One of the fundamental questions in biogeography is how paleoclimate and paleogeology shape biotic distribution. However, to understand these processes at different time frames, one needs to look at patterns at both intra and inter-species and levels. Freshwater gastropods owing to their ecology are particularly susceptible to environmental fluctuations and therefore are an ideal model system to study these processes. In my first two chapters, I have investigated the origin and evolution of two snail families, Ampullaridae and Viviparidae. Here, I explored the role of tectonic history of India and several paleoclimatic and paleogeological events in shaping their distribution in the Indian subcontinent in a phylogenetic framework. In the third chapter, I have addressed how late Quaternary climatic fluctuations have affected the distribution and demography of two species of Viviparidae snails: Bellamya bengalensis and B. cf. dissimilis, in the subcontinent using phylogenetic and population genetic tools as well as statistical phylogeographic inference. I discuss how these various abiotic factors have affected the distribution of these snail species at different geological time frames and levels of biological organization.