Professor Vinod Chandra Tewari
Senior Scientist (Geology), Astrobiologist, India
Professor Vinod Chandra Tewari recently retired (November 2014) as Senior Scientist (G) and Project Director at Wadia Institute of Himalayan Geology, Dehradun, India. He has done extensive research for over 35 years in the field of Precambrian Phanerozoic stromatollites; sedimentation and carbon isotope chemostratigraphy; genesis, early evolution and diversification of life and its astrobiological significance. In his illustrious scientific career, he has been awarded many international fellowships. He was the senior associate and TRIL fellow at the International Centre for Theoretical Physics, Trieste, Italy. He has contributed to several International Geoscience Programme (IGCP) projects such as stromatolites, bio-sedimentology of microbial buildups, phosphorites, Precambrian – Cambrian boundary, global bioevents and the rise and fall of Vendian biota. He is currently the convener of the IGCP project on Asian Tethyan Realm in India. It is a huge multinational project which, through multidisciplinary investigations, is expected to yield immense data regarding paleobiogeographic evolution of Asia. Professor Tewari has been on the editorial board of several high profile journals like the International Journal of Astrobiology (New York, USA) and special Issue of the Elsevier Journal “PALEO-3”. He has also edited several volumes of Himalayan Geology Journal (Dehradun India), Journal of Indian Geological Congress (Roorkee, India) and Journal of Nepal Geological Society (Kathmandu, Nepal). He has more than hundred research articles in reputed journals to his credit. He has written several books in Hindi too. Being keenly interested in popularization of astrobiology, currently he is actively involved in teaching Astrobiology in various central universities in India.
Interviewed by Dr. Preeti Nema, Research Scientist, Blue Marble Space Institute of Science.
Welcome to Astrobiology India, Professor Tewari. It is an honor to have you with us today for our Meet an Astrobiologist segment! Please tell us something about your educational background and your career path to astrobiology.
I got my B.Sc., M.Sc. (Geology) and Ph.D. (Stratigraphy and Sedimentology) from University of Lucknow, Uttar Pradesh, India. I started my research career as a Junior Research Fellow (JRF) at the Wadia Institute of Himalayan Geology (WIHG), Dehradun and later joined the institute as a professional scientist. I recently retired after being at the institute for 36 years. During my long research career, I mainly worked on the sedimentary basins of the north western and north eastern Himalayas, focusing on the sedimentological, paleobiological, stable isotopic and geomicrobiological aspects. I developed interest in the origin, evolution, diversification of life and astrobiology, while studying the Proterozoic stromatolites and microbial assemblage associated with the black cherts in the lesser Himalayan and equivalent rocks of India, Russia and elsewhere. My first visit to Russia (formerly Soviet Union/USSR) was for a collaborative research with scientists in Russia, in 1986-87 in Moscow (with M.E. Raaben, M.A. Semikhatov, V. Komar, J. Koroljuk, A. Rozanov, M. Fedonkin), in Leningrad (with M. Gniloskaya), and in Novosibirsk (with V. Khomentovsky) and was very fruitful. I organized the first Indo–Soviet symposium on Stromatolites and Stromatolitic deposits at the WIHG in 1988. I became the member of the International Society for the Study of the Origin of Life and Astrobiology (ISSOL, USA) during the conference held in Prague in 1989, and since then I regularly participated and contributed papers in the subsequent conferences held every four years (Orleans, France, San Diego, California, and Beijing, China). Astrobiology became my main interest while I was studying the highly diversified microorganisms (cyanobacteria etc.) and micro-stromatolites from the Buxa stromatolitic cherty dolomite from Sikkim and Arunachal lesser Himalaya which was further published with professor J.W. Schopf, at the University of California, Los Angeles (UCLA), in the International Journal of Astrobiology (New York) in 2008. We (Schopf and I) jointly organized the World Conference on Ancient Microfossils with the support of Center for the Study of Evolution and the Origin of Life at UCLA and NASA Astrobiology in 2008. Our focus was to use Laser Raman Spectroscopy and Confocal Laser Scanning Microscopy (CLSM) techniques on the oldest microfossils on Earth and for possible life on Mars (with a future Mars sample return mission). I also worked on astrobiology and origins of life topics at the International Centre for Theoretical Physics (ICTP), Trieste, Italy as a Regular Associate (1998- 2001) and later as a Senior Associate (2002-2008) in the Biophysics group and mainly aimed at the possible occurrence of life on Europa and Mars. I co-organized the World Summit on Ancient Microfossils, at UCLA, in 2008, and also organized scientific sessions on pre-Mesozoic Paleoclimate at the 34th International Geological Congress (IGC) in Brisbane, Australia, in 2012. In future, I plan to organize more scientific sessions at the 35th IGC to be held in 2016, in Cape Town, South Africa, on astrobiological, geo-microbiological and geological aspects. While I was working at the ICTP, Italy, as a Senior Associate, I interacted with leading astrobiologists like professor Frank Drake from the SETI Institute, professors David McKay and Chris McKay from NASA, and professors Miller, J. Oro, J. Seckbach, Julian C. Flores, and many more. An informal group of the Indian astrobiologists was also created at ICTP, to popularise astrobiology in India.
Fig 1: Astrobiology research group of ICTP in Trieste, Italy few years back (Professor V.C.Tewari in the centre and Professor J. Chela Flores, former head in the right)
That’s amazing. So, studying stromatolites got you interested in this field. Could you please explain to our readers, what are stromatolites and what is their astrobiological significance?
Stromatolites are formed by the interaction of microbes with sediments and therefore, are organo-sedimentary in origin. Generally, the photosynthetic cyanobacteria (filamentous and coccoid forms) are considered to have formed these structures on Earth, based on the occurrence of the modern stromatolites such as those found in Shark Bay, Australia and elsewhere. Stromatolites have been recorded from carbonate rocks of all geological ages, from Precambrian to recent. Stromatolites found in the Proterozoic formations worldwide have been used for global biostratigraphic correlations which help astrobiologists in understanding the evolution of life on earth.
Fig 2: Filamentous Microfossil assemblage discovered from the Meso-Neoproterozoic Buxa Dolomite, Ranjit Window, Sikkim, Northeast Lesser Himalaya. (Credit: Schopf et al., 2008, Astrobiology, Vol 8 , No. 4, pp.735- 746)
Where can we find stromatolites in India?
In India, one can find the best developed unique Paleoproterozoic stromatolites associated with phosphorites in the Aravalli rocks of Rajasthan in western India. The Meso and Neoproterozoic stromatolites are well known in the Vindhyan and Chhatisgarh basins of Central India. Stromatolites have been recorded from the Jammu Limestone, Dharamkot Limestone, Shali-Larji Limestone, in the northern and eastern parts of India (lesser Himalaya); Deoban – Gangolihat Limestone in the north west Himalaya, and Buxa Dolomite in parts of Arunachal and Sikkim. You can find a detailed account of all Indian and global stromatolite occurrences in our book ‘Stromatolites: Interaction of Microbes with Sediments’.
Fig 3 : Field occurrence of transverse section of conical stromatolites (Conophyton sp.) in the Buxa Dolomite, Sikkim Himalaya.
What significance do microfossils from Himalayan region have in terms of the history of origin of life?
The first evidence of megascopic life on Earth is the occurrence of stromatolites from Australia (3.4 billion years) formed by microorganisms. There is diversification of life from Archean to Proterozoic and that is recorded as a diverse assemblage of stromatolite taxa in India including Himalayas. There was an evolutionary change in the microorganisms in the Ediacaran period after the Neoproterozoic glaciation (the snowball Earth event) where we start getting complex acritarchs and multicellular soft bodied organisms and algae (Vendotaenids) etc. These microorganisms are also found in the lesser Himalayan sediments after the Blainian glaciation. Therefore, the microorganisms are quite significant in the understanding of unicellular to multicellular evolution and diversification bio-event of the life in the Himalayas and on Earth and also, find immense application in the interpretation of paleoclimate.
Two years ago, there was a lot of buzz about the Russian meteorite. It is said that geochemistry of meteorites can reveal information about life in the Universe. You have also done research on a meteorite sample from Rajasthan (India). Could you please share with us, your findings from that study?
The astrobiological investigations of meteorites falling on Earth from the asteroid belt, situated between the orbits Mars and Jupiter in our solar system, have confirmed the presence of amino acids and other organic compounds using Laser Raman Spectroscopy. We studied the Didwana Rajod Meteorite (DRM), from the Didwana area in Rajasthan, western India, for presence of biomolecules (amino acids) and possible presence of microorganisms. The Raman spectra and shifts in the wave numbers confirmed the identification of various types of organic compounds, amino acids (tyrosine, phenylalanine, tryptophan), and kerogen etc. These aromatic amino acids are quite significant for additional search of extraterrestrial amino acids in other meteorites. The petrographic thin sections of the DRM showed well developed chondrules (see picture). Some microfossil-like structures have also been observed in the petrographic thin sections under scanning electron microscope (SEM).
I am sure many of our young student readers who wish to be geologists, would now be eager to learn more about astrobiology. Could you please suggest some books for beginners in Astrobiology from a geologist’s point of view?
There are many books published in the recent years on the topic of astrobiology and these books also contain chapters on geological aspects or geobiology/geomicrobiology etc. I would recommend the following books-
- Earth’s Earliest Biosphere, Its Origin and Evolution – Schopf, J. W. (1983), Princeton University Press, Princeton
- Stromatolites and Stromatolitic Deposits, Himalayan Geology (Volume 13) – Valdiya, K. S., & Tewari, V. C. (1989), Wadia Institute of Himalayan Geology, Dehradun, India
- The Proterozoic Biosphere: A Multidisciplinary Study – Schopf, J.W & Klein, C. (1992), Cambridge University Press, New York
- Life on a Young Planet: The First Three Billion Years of Evolution on Earth – Knoll, A. H. (2003), Princeton University Press, Princeton
- Introduction to Geomicrobiology – Konhauser, K. (2007), Blackwell, Malden
- From Fossils to Astrobiology: Record of Life on Earth and the Search for Extraterrestrial Biosignatures – Seckbach J. & Walsh, M. (2009), Springer, COLE Volume, 12
- Stromatolites: Interaction of Microbes with Sediments – Tewari, V. & Seckbach, J. (2011), Springer, COLE Volume 18
- The Science of Astrobiology – Chela-Flores, J. (2011), Springer, COLE, Volume 20
That’s an absolutely wonderful list of resources. Thank you for sharing. In your opinion, what is the current scenario of astrobiology education in India?
Astrobiology education in India is not that organised, at the moment, but slowly universities and colleges are catching up. Many colleges and universities have now started including astrobiology in their curriculum. Recently, astrobiology lectures were organized for the students of the B.Sc and M.Sc. integrated course by the Geology Department of Sikkim Central University from 3rd to 15th June, 2015. I delivered lectures on topics like, the origins, evolution, distribution and future of life on Earth and the search for life beyond the Earth. Slides with pictures containing evidence of earliest life on Earth (stromatolites and cyanobacterial microfossils etc.) as well as those of petrographic thin sections were shown. The new techniques of laser Raman spectroscopy and confocal scanning microscopy for the study of microfossils in 3D were explained and demonstrated. These techniques will be used in future to study possible Martian microscopic life. The major catastrophic extinction events of life on Earth brought about by asteroid/meteorite impacts were also explained. One of the lectures was on major meteorite types recorded on Earth (Murchison, ALH 84001, SNC Group, Didwana-Rajod).The lectures were well received by the students. Such exposure is really important for students. Now, I wish to have an institute completely devoted to astrobiological research somewhere in India and be called as the Indian Institute of Astrobiology (IIA).
Fig 4: Students at Geology Department of Sikkim Central University attending Astrobiology lectures by Professor V.C. Tewari
Other than astrobiology research, what are the things that interest you?
I like adventures and love to travel to different places. Trekking in the Himalayas, practicing meditation, and listening to Indian classical music are my hobbies.
What advice do you have for young students who aspire to be astrobiologists/geologists?
I always encourage young school/college students to have interest in astrobiology and geology because these topics of science are at the frontier of future. I deliver popular lectures in different parts of India, especially in the developing areas of the Himalayas. To create interest amongst the students and the local people for astrobiology, in understanding our Indian philosophy of the Universe (Brahmanda), Earth and origins of life etc., and also give them advice on how to preserve our rare geological structures and fossils as local geoparks for the future generation. I especially encourage Indian students to consider some of our highly successful space programs, such as the Chandrayaan Mission and the Mars Orbiter Mission (MOM), conducted by the Indian Space Research Organization (ISRO), which promise to offer multiple opportunities in space science, space technology, astrobiology, and astrogeology, in future.
Before we wrap this up, we would love to hear your views and suggestions for our new initiative- Astrobiology India.
It is a very good initiative to connect Indian astrobiologists and the global astrobiology fraternity to promote this emerging frontline area of space research and teaching. In India, there is a vast scope to develop and popularise astrobiology among students and early career scientists. The Indian network of astrobiologists should emphasis teaching astrobiology courses in Indian universities. They should encourage research discussions on astrobiological aspects through the participation of microbiologists, geologists, molecular biologists, astrophysicists and biochemists. More members should be encouraged to join the group and contribute. The Indian research institutes like (ISRO), Birbal Sahni Institute of Paleobotany (BSIP), WIHG, Physical Research Laboratory (PRL), Centre for Space Physics (CSP), Centre for Cellular and Molecular Biology (CCMB), and various universities as well as the Indian Institutes of Technology (IITs) could be involved in collaborative research on astrobiology in India. The international collaborative projects on astrobiology with NASA, European Space Agency (ESA), Australia, Japan, and Russia could be initiated through our national space agencies and personal collaborations. Astrobiology India can play a vital role in bringing together Indian and global astrobiologists for this exciting field of science, keeping in mind India’s future space missions planned by ISRO. Wish you all the success for Astrobiology India Initiative.
Thank you very much, Professor Tewari, for your kind words of encouragement and hopes! We are constantly making efforts to bring the Indian as well as international astrobiology community together to carve a niche for astrobiology in India. Many thanks for this informative and inspirational Q & A!