After obtaining a PhD in molecular biology, I made an unusual twist in my career and turned my attention to the study of social insects.I have chosen the locally available Indian species of primitively eusocial wasp Ropalidia marginata. I and my team of students have pursued empirical and theoretical, field and laboratory, work on this single species for over 30 years. We have used a variety of approaches in our research, including biochemical and molecular techniques to show that queens mate multiply and mix sperm from different males, construction of pedigrees to show that workers rear rather distantly related brood, experiments to demonstrate that workers are unlikely to discriminate between different classes of relatives and that all individuals are not equally fit for social or solitary life. I developed a new class of theories, the focus of which is demography, a factor previously unexplored in this context. My “Assured Fitness Returns” model is an example of how group living can confer advantages over solitary life that are independent of genetic relatedness.
We also pursue, in parallel, an equally rigorous programme of experimental and theoretical work focusing on proximate questions of social organization and queen-worker interaction. We have discovered behavioural caste differentiation, pre-imaginal caste bias and a honey bee like age polyethism, in this species that lacks morphological castes. We have demonstrated that queens of R.marginata are behaviourally docile, meek sitters. This raises questions regarding how such queens become queens in the first place, how they inhibit worker reproduction and how they regulate non-reproductive activities of their workers. Attempts to answer these questions have begun to suggest that R.marginata queens start their career as aggressive queens and probably switch to pheromonal control of worker reproduction, which is why they can afford to be behaviourally meek sitters. As a response to this behaviour on the part of their queens, the workers have responded by self-organizing their own non-reproductive activities and thereby gaining indirect fitness without much prodding by the queen. Another remarkable feature of Ropalidia marginata society is the smooth and conflict-free succession that happens from one queen to the next. Through a series of experiments, we have demonstrated that even though human observers cannot predict the identity of the successor, the wasps themselves appear to know who the successor would be in the event of the death or loss of the queen. Indeed we have demonstrated that there is a long reproductive queue of cryptic successors with designated positions in the queue and all this happens in the presence of the old queen.
As the founder chair of the Centre for Contemporary Studies at IISc, Bangalore, I have initiated a new experiment that endeavours to engage some of the best practitioners of different disciplines in the human sciences, such as philosophy, sociology, economics, law, literature, poetry, art, music, cinema etc. and aims to forge meaningful interaction between the natural and human sciences with special focus on exposing graduate students to the diverse research methodologies of different disciplines and thus creating opportunities for them to rethink the foundations of their own disciplines.
Chakraborty, S., Bhadra, A., Nandi, A. K., Annagiri, S., Deshpande, S., Lamba, S., Bang, A. and Gadagkar, R. (2018). Evolution of reproductive dominance in animal societies – lessons from a social wasp. Proceedings of the Indian National Science Academy. doi: 10.16943/ptinsa/2018/49310. Brahma, A., Mandal, S. and Gadagkar, R. (2018). Current indirect fitness and future direct fitness are not incompatible. Biology Letters. 20170592. dx.doi.org/10/1098/rsbl.2017.0592. Saha, P., Nandi, A.K., Unnikrishnan, S., Shilpa, M. C., Shukla, S., Mandal, S., Mitra, A. and Gadagkar, R. (2018). A Route to Direct Fitness: Natural and Experimentally Induced Queen Succession in the Tropical Primitively Eusocial Wasp Ropalidia marginata. Journal of Insect Behavior. doi.org/10.1007/s10905-017-9657-6. Chakraborty, S., Shukla, S. P., Arunkumar, K.P., Nagaraju, J. and Gadagkar, R. (2017). Genetic relatedness does not predict the queen’s successors in the primitively eusocial wasp, Ropalidia marginata. J. Genetics, in press. Brahma, A., Mandal, S. and Gadagkar, R. (2018). Emergence of cooperation and division of labor in the primitively eusocial wasp Ropalidia marginata. Proceedings of the National Academy of Sciences, USA, 115, 756-761. doi:10.1073/pnas.1714006115. Gadagkar, R. (2018). Choosing a New Queen: Consensus without Conflict in a Social Wasp Colony. In: Landscapes of Collectivity in the Life Sciences. (Eds.) S.B. Gissis, E. Lamm and A.Shavit, The MIT Press, Cambridge, Massachusetts, pp.67-75. Sridhar, H. and Gadagkar, R. (2018). Standing conventional wisdom on its head: an interview with Raghavendra Gadagkar. Dialogue – Science, Scientists, and Society. 1 (1). doi:10.29195/DSSS.01.01.0004. Gadagkar, R. (2018). Why does our society lack scientific temper and what can scientists do about it? Confluence, Indian Academy of Sciences, 2 January. (originally published in Journal of Scientific Temper, 2016, 4, 57-60). http://confluence.ias.ac.in/why-does-our-society-lack-scientific-temper-... Gadagkar, R. (2017). Ant, Bee and Wasp Social Evolution. In: Reference Module in Life Sciences, Elsevier. doi:10.106/B978-0-12-809633-8.01024-4 (Revised version of serial no. 246). Gadagkar, R. (2017). A Tale of Science, Passion and Politics. A Review of – How to Tame a Fox (and Build a Dog) – Visionary Scientists and a Siberian Tale of Jump-Started Evolution by L.A. Dugatkin and Lyudmila Trut, The University of Chicago Press, Chicago and London (2017). Proc. Indian Natn. Sci. Acad. 83, 973-975. doi.10.16943/ptinsa/2017/49222.
Member, German National Academy of Sciences Leopoldina, 2012. Millennium Plaques of Honour, 2010, Indian Science Congress Association, Kolkata. INSA S.N. Bose Research Professorship, 2010 –2015.
H.K. Firodia Award 2008 for Excellence in Science & Technology, 2008.
Elected Foundation Fellow, Entomology Academy of India, Chennai, 2007.
Award of Jawaharlal Nehru Birth Centenary Visiting Fellowship – 2007 of the Indian National Science Academy, New Delhi.
JC Bose National Fellowship, Department of Science & Technology, Government of India, 2006-2011.
Elected Foreign Associate, National Academy of Sciences, USA, 2006.
Member, Indian Delegation to participate in the meetings of the Inter-academy Panel held in Shanghai and the International Council for Science held in Suzhou, China, October 2005.
Prof. U.S.Srivastava Memorial Lecture Award of the National Academy of Sciences, India, 2005.