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Colloquium on the origins of modern Indian biodiversity  Mar 06, 2020

IISER Pune is happy to announce:


Institute Colloquium 2020:


The origins of modern Indian biodiversity: Climate implications


Prof Ashok Sahni, Professor Emeritus, ONGC Chair, Panjab University, Chandigarh

(See flyer)



DateFriday, March 6, 2020


Time: 5:15 pm

Venue LHC 103, Lecture Hall Complex, IISER Pune


The present-day biodiversity of South Asia is unique in many ways. It reflects the epic journey that the Indian Plate made from its base next to Madagascar (40o S) to its present position in Asia. As it drifted along, several biotic elements boarded the island subcontinent, yet many became extinct. Many forms were inherited from the southern continents or originated as India drifted northwards, a journey that took about 90 million years, notable amongst these are the Shorea (Saal) tropical evergreen forests, the grasses, the social insects (ants , termites , bees), whales, and haplorhine tarsier-like primates. Contrast this complexity to that of Australia, its giant and more passive neighbour in Gondwanaland which still retains a sizable portion of the marsupial fauna that it inherited over 100 million years ago.
Biodiversity is everchanging in areas where climate change is rapid. The Indian Plate as it drifted rapidly towards Asia passed through temperate, equatorial and tropical climatic regimes. Superimposed on these climate zones were three global climate events that affected biodiversity: 65-66 million years ago, a major extinction wiped out near 65-70% of the earth’s biota including the dinosaurs concomitant with the eruption of the Deccan volcanic eruptions and an asteroid impact; and second, around 56 million, the earth experienced several bouts of thermal warming turning the earth into a runaway greenhouse; and third, the rise of the Himalaya and the Tibetan Plateau and the onset of the monsoon regime.
My studies along with others, have established that several new mammal types originated during the greenhouse period. Many of these evolving forms have modern day counterparts. One remarkable event is the origin of whales in India and Pakistan around 53 million years, and their spread around the global oceans. Modern biodiversity in India has been established in several stages and is still changing as India pushes into Asia at about 3-5 cm every year causing the northwestern region of the subcontinent to become higher, colder and drier. As a result, many warm tropical organisms migrated to and sought refuge in SE Asia as the Himalaya and Tibet elevated.

All are welcome to attend.