Profile of Raghavendra Gadagkar aghavendra Gadagkar is in love Science Talent Search Examination and with Ropalidia marginata,a won a scholarship that enabled him to species of red–orange paper attend Bangalore University (Bangalore, wasp found in southern India. India; called Central College at the R‘‘And boy, isn’t it a beautiful wasp,’’ he time). If he had not won the scholarship, wrote in a ‘‘guest feature’’ article to ap- he probably would have been relegated to pear in a textbook on social behavior (1). a 2-year college for undergraduates. ‘‘I have been stung dozens of times The advantage of the university did but never complained. I guess that’s not lie in its teaching, according to what love does to you,’’ he says in the Gadagkar, which he found dull and de- book. void of challenge. It lay in the universi- The evolution of social life fascinates ty’s active research program. Gadagkar. He chose to study R. mar- ‘‘Right from the first year I was di- ginata because its social behavior is at rectly in contact with graduate students an intermediate stage of development, working toward a PhD and other re- allowing him to observe how the rudi- searchers,’’ he said. He spent most of ments of complex behavior emerge. his time talking to the research scholars Although all R. marginata wasps in a and pursuing research projects of his nest appear identical, including the own. queen, they assign themselves distinct Classes at Central College may have roles, and the organization of the nest bored him, but Gadagkar found inspira- as a whole shares certain sophisticated tion in the classrooms themselves. ‘‘Al- aspects of behavior with more advanced most every window of the college had insect societies. Raghavendra Gadagkar nests of these little wasps [R. mar- ‘‘I think the wasps hold a mirror to us ginata],’’ he said. ‘‘They were fascinating and allow us to reflect on our own soci- to watch. They built a honeycomb-like ety,’’ he said, ‘‘not in the sense of imi- military postings, and Gadagkar did not structures, but much smaller. Usually no tating them, but trying to understand begin formal schooling until he would more than 3, 4, 5 centimeters in diame- what we might do under certain normally have been in third grade. The ter, and there are 20, 30 individuals circumstances.’’ administrators wanted to place him in working together, going out, bringing Gadagkar is a professor at the Centre the first grade. As a compromise with food, feeding the larvae, fighting. It was for Ecological Sciences, part of the In- his parents, they agreed that he could great fun to watch them as a layman.’’ dian Institute of Science in Bangalore, try the second grade. Gadagkar finished his BSc in zoology India. He has studied R. marginata al- He soon demonstrated such promise, in 1972 and earned a MSc degree, also most exclusively for 30 years and is the however, that he was permitted to over- in zoology, in 1974. For graduate stud- world’s foremost expert in the behavior take his classmates and catch up with ies, he applied to the Indian Institute of of these wasps. He was elected a For- kids of his age. Science (IISc). The institute was ‘‘argu- eign Associate of the National Academy ‘‘I made up for lost time,’’ he said, ably the best scientific research institute of Sciences in 2006. In his Inaugural ‘‘and yet I had this great freedom as a in the country,’’ he said. Upon his ac- Article, he gives readers a tour of some kid which I enjoyed thoroughly. I think ceptance he was offered the only avail- of the most important questions he and that allowed me to watch bugs and able seat that year for pursuing a doc- his students have considered during his butterflies!’’ torate degree in molecular biology. career (2). In the eighth grade, Gadagkar had to ‘‘I was equally interested in molecular choose between science and the arts and biology on one hand and animal behav- In Search of Lost Time humanities. The specialization was so ior on the other,’’ he said, ‘‘but at that extreme that students even had to Gadagkar was born in 1953 in Kanpur time you could do only one of them. I choose a subfield. in the Indian province of Uttar Pradesh. took the opening, but I continued to ‘‘At that age it was completely inexpli- In 2008, before Gadagkar received the watch wasps as a hobby.’’ cable to me why you couldn’t do both H. K. Firodia Award, given annually to During his PhD studies, Gadagkar arts and literature and science together, mastered the techniques of modern mo- recognize world-class contributions by but in India it was unthinkable,’’ Gada- Indian scientists, he filled out a ques- lecular biology. Under the supervision gkar said. ‘‘I had no possibility of pursu- of K. P. Gopinathan, he conducted stud- tionnaire that aimed to reveal details of ing both simultaneously. So I chose biol- ies on mycobacteriophage I3. his life that someone who knew him ogy, but it was much to my regret that I He graduated in 1979, and soon after only from his research would never have couldn’t also continue studying mathe- he married Geetha, whom he had met learned. To a question about his family, matics and physics and in fact literature at Central College. The couple spent he replied: and arts, which I was very interested in.’’ 5 years apart while Geetha taught biol- Gadagkar credits his biology teacher ‘‘My father, a strict disciplinarian, ogy in Nainital before she joined him Mr. Chacko with drawing him to the was my great source of inspiration. at IISc. He was a man of great moral and subject, away from Hindi literature, ‘‘which was another of my great passions ‘‘My wife has made it possible for me physical courage. His wish that I ex- to merge profession with hobby, work cel in ‘studies’ has remained the at the time,’’ he said. strongest motivator of my life.’’ Windows of Inspiration This is a Biography of a recently elected member of the His father was an officer in the Indian In his final year of high school, Gada- National Academy of Sciences to accompany the member’s Air Force. The family moved often for gkar entered India’s prestigious National Inaugural Article on pages 10407–10414.

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with vacation, and office with home,’’ Eusocial questions include: why do Gadagkar said. these insects live collectively? What evo- lutionary benefits do they gain? Humans A Very Important Species have diploid genomes, with 1 copy from At IISc, Gadagkar met Madhav Gadgil, the mother and 1 from the father; a mathematical biologist who had hence, an individual is related equally to worked with Harvard’s E. O. Wilson. his or her siblings and offspring, sharing ‘‘Gadgil had actually written a small 50% of one’s genetic material with each. note on Ropalidia marginata shortly be- But in Hymenoptera, the system of fore I met him,’’ Gadagkar said. ‘‘One haploidiploidy operates, in which fe- day I told him ‘I know lots of these males have 2 copies of the genome, but wasps, if you are interested in studying males have only 1, which they receive them.’ He said, ‘No, I am not studying entirely from their mothers. As a conse- them, but if you want to study them, I quence, a female individual is related by can help you.’ He led me to some of the 50% to its offspring and 75% to its sis- literature. I started reading E. O. Wil- ters, which makes it more profitable to son’s articles. And then it turned out ensure the genetic success of siblings that this species belongs to one of the rather than investing resources in most important groups for understand- mating. ing the evolution of insect social behav- The evolutionary biologist W. D. ior. It came as a great surprise to me.’’ Hamilton proposed a theory of selection Gadagkar had still not decided which Ropalidia marginata. in which an individual aids another if interested him more: animal behavior or the cost of the action is less than the molecular biology. ‘‘Again I was willing benefit to the recipient multiplied by the even thousands of wasps, and they are to go off in either direction,’’ he said. fraction of genetic material shared by all on my computer files. Having done ‘‘And the choices before me were some- the two. that, over many, many days of observa- what different. It was obvious to me Based on Hamilton’s theory, hap- tion, I actually computed what we call that if I wanted to do animal behavior, loidiploidy had been put forward as the time-activity budgets, for every wasp.’’ then there is no better place than the prime reason for the emergence of euso- tropics of southern India. But it was also He found that even though R. mar- ciality. But over his career, Gadagkar clear to me that if I wanted to do exper- ginata does not have morphological has amassed evidence that shows that iments in molecular biology then I castes, there are behavioral castes. ‘‘I the cost and benefit factors greatly would really be much better off moving called them sitters, fighters, and forag- outweigh the relatedness term in to the United States or to Europe where ers,’’ he said. ‘‘The sitters are fairly mild importance (5). the technological sophistication is much individuals who seem to do little. The He explained this phenomenon and greater. fighters are the aggressive ones. They’re many others in a book-length mono- ‘‘It became a choice between living in all of the time attacking and fighting graph he published on R. marginata in the US or living in India. I readily chose and policing others. And the foragers 2001 (6). to live in India, and that’s why I chose are hard-working. They go out of the ‘‘When a female wasp becomes an to continue work on these wasps. I was colony, they bring food.’’ adult, she has several options open to quite easily able to convert my hobby The members of a nest, he showed, her,’’ he said. ‘‘She can stay for the rest into my full-time profession.’’ learn to recognize one another by smell- of her life as an altruistic worker and He admitted that he was tempted to ing each other as adults (4). Aliens work for her mother or her queen. Or, branch out and study other species of smell strange and are fought off; selfishly, she can also leave. She can social insects, but made a conscious de- nestmates are welcomed. He found that build her own nest, lay her own eggs, cision to go deep rather than broad. the genetic material carried by a wasp guard them, and bring her offspring to ‘‘And I have stuck to that decision,’’ does not necessarily determine its status. adulthood. he said. ‘‘That’s why I have spent more ‘‘In one of the experiments we had ‘‘Now we have reached a stage where than 30 years now studying this one spe- great fun doing,’’ he said, ‘‘we were able we are actually able to make predictions cies. I believe there’s enough to last the to take some of the wasps out of their about what percentage of the population rest of my lifetime or more.’’ nest before they became adults and rear of wasps should opt for the altruistic them in an incubator. Then we brought role and what percent should opt for the Order from Chaos them back to the nest. We found that selfish role. When we go into the field When an untrained observer looks at a those wasps had no clue as to which and measure these proportions, there is R. marginata nest, all of the wasps look nest they belonged to. You can also fool a very striking fit between what we pre- the same and appear to be doing the a colony by bringing in very young alien dict and what we observe, which gives us same things, even the queen. (Only fe- wasps. They are accepted and then they confidence that the theory is valid.’’ males live in the nest.) One of Gada- become card-carrying members of the gkar’s first achievements was to develop nest. In some cases they might even go Queen’s Gambit a system for keeping track of all of the on to become queens in the future.’’ Much of Gadagkar’s work has focused wasps in a nest and following their activ- on how a hierarchy of duties is estab- ities over several days (3). The Origins of Eusociality lished in the nest and how a queen can ‘‘I did something which was at that This work also touched on a central emerge from an apparently uniform time quite unusual,’’ he said. ‘‘I individ- theme in Gadagkar’s research: the ori- population of wasps. ually marked all of the wasps in the col- gins of eusociality, or complex social ‘‘The wasps belong to 3 groups (sit- ony, so that I could recognize each one. organization, in Hymenoptera. The Hy- ters, fighters, or foragers) and the queen I developed a system of naming them, menoptera order includes ants, bees, and has to belong to one of these,’’ he said. which allows me to name hundreds or wasps. ‘‘Common sense suggested that the

Mossman PNAS ͉ June 30, 2009 ͉ vol. 106 ͉ no. 26 ͉ 10405 Downloaded by guest on September 29, 2021 queen should be a fighter. In other spe- periments in which he and his students walks of academia. He also cannot help cies the queens are very aggressive to cut a colony into halves, separated by making quasi-scientific observations prevent the workers from taking over wire mesh, the pheromone appears to about their social behavior, which he the colony, start reproducing, laying be nonvolatile. The queen applies it once analyzed in an official publication eggs, developing their ovaries, and so from her body to the nest as she moves of the institute (11). on. But to our great surprise we found around (9). He was elected a permanent fellow of that she is not a fighter, she is a sitter. the Institute in 2002 and has returned In colony after colony, the queen is al- regularly over the past 8 years. Gada- ways a sitter.’’ ‘‘I think the wasps hold gkar’s experience at the Wissenschafts- But R. marginata are certainly not all kolleg inspired him to found a sister passive. Gadagkar had identified one a mirror to us and allow center in Bangalore. class as fighters. ‘‘We wanted to know ‘‘I have spent almost all my life at the why the workers show aggression to us to reflect on our IISc since I left college,’’ he said. ‘‘I’ve each other,’’ he said. ‘‘So we considered loved every minute of it, but the [In- how the queen becomes a queen in the own society.’’ dian] Institute was completely closed to first place, if she is such a meek, docile, social scientists and those who study hu- nonaggressive individual. We removed manities, art, and literature. It was the queen, to see how a new queen Gadagkar and his team have also in- about science only. And this I found emerges. We found that when you re- vestigated how wasps organize the divi- very narrowly focused and was quite move the old queen, one of the workers sion of labor in the nest. ‘‘In other spe- unhappy about it and I always in the colony becomes extremely aggres- cies of this kind, if a worker brings some complained.’’ sive. She steps up her aggression 10-, food and then simply remains on the Nearly 4 years ago, the Institute de- 20-, even 30-fold sometimes. And that’s nest, the queen will bite her, force her cided to create a Centre for Contempo- how she becomes a new queen’’ (7). to go and bring more food. Our queen rary Studies. Gadagkar has since served It might seem obvious that the aggres- is not doing any of that. It’s hard to as the center’s chair. sion is to overcome challenges from oth- imagine that she releases a chemical ‘‘I bring some of the best people in ers, but Gadagkar and his students have that said go and bring more food.’’ the world in every branch of human found that the reason for the aggression Physical aggression between the work- knowledge, including philosophy, art, is that it accelerates the development of ers is used to convey hunger signals literature, cinema, poetry, law, econom- the queen’s ovaries (8). from the larvae to the foraging wasps. ics, and psychology,’’ he said, ‘‘and I He said, ‘‘We now have evidence that give an opportunity for them to talk to Scent of a Woman the workers regulate their own activities the scientists on this campus, particu- ‘‘Now this answer leads to another ques- in a decentralized, self-organized, sort of larly the students. We hold debates tion,’’ he said. ‘‘If she becomes meek bottom-up control’’ (10). about things like objectivity, how knowl- and docile very quickly, how does she edge is evaluated, and whether it can be prevent the workers from taking over? A Wider Perspective replicated. Because she would then reign on the Gadagkar completed the final drafts of ‘‘This allows the students to get this colony for several weeks or several his monograph on R. marginata during larger perspective, to say, yes, here is a months but her authority is never ques- an invited fellowship at the Wissen- historian, he does things very differently tioned. But she’s aggressive only for a schaftskolleg zu Berlin (the Berlin Insti- from the way I do as a biologist. Why? week. So how does she do that? We tute for Advanced Study). Is it completely wrong? It allows them now have growing evidence that she He is a deft and entertaining writer to ask these questions. And very often it allows them to start thinking about their uses a pheromone to prevent the other and counts science writing as one of own science. So this is what I am doing workers from reproducing.’’ many interests. This multiplicity of skills at the Centre for Contemporary Studies. Gadagkar’s research group is cur- and tastes enabled him to enjoy his time It’s been hugely successful.’’ rently looking into the nature of this in Berlin immensely; he values the pheromone. Based on the results of ex- chance to interact with scholars from all Kaspar Mossman, Science Writer

1. Gadagkar R (2009) In love with Ropalidia marginata implications for the evolution of sociality. Behav Ecol itively eusocial wasp Ropalidia marginata. Behav Pro- for 34 years, and still going strong. Social Behavior: Sociobiol 23:271–279. cesses 74:351–356. Genes, Ecology, and Evolution, eds Szekely T, Moore 5. Gadagkar R (1991) Demographic predisposition to the 9. Sumana A, Deshpande SA, Bhadra A, Gadagkar R AJ, Komdeur J (Cambridge Univ Press, Cambridge, evolution of eusociality: A hierarchy of models. Proc (2008) Workers of the primitively eusocial UK), in press. Natl Acad Sci USA 88:10993–10997. wasp Ropalidia marginata do not perceive their 2. Gadagkar R (2009) Interrogating an insect society. Proc 6. Gadagkar R (2001) The Social Biology of Ropa- queen across a wire mesh partition. J Ethol 26:207– Natl Acad Sci USA 106:10407–10414. lidia marginata (Harvard Univ Press, Cambridge, 212. 3. Gadagkar R, Joshi NV (1983) Quantitative ethology of MA). 10. Premnath S, Sinha A, Gadagkar R (1995) Regulation of social wasps: Time-activity budgets and caste differen- 7. Chandrashekara K, Gadagkar R (1991) Queen succes- worker activity in a primitively eusocial wasp, Ropalidia tiation in Ropalidia marginata (Lep.) (Hymenoptera: sion in the primitively eusocial tropical wasp Ropalidia marginata. Behav Ecol 6:117–123. Vespidae). Anim Behav 31:26–31. marginata (Lep.) (Hymenoptera: Vespidae). J Insect 11. Gadagkar R (2006) 25 Jahre Wissenschaftskolleg 4. Venkataraman AB, Swarnalatha VB, Nair P, Gadagkar R Behav 5:193–209. zu Berlin: The Evolution of a Biologist in an (1987) The mechanism of nestmate discrimination in 8. Lamba S, et al. (2007) A possible novel function of Interdisciplinary Environment (Akademie Verlag, the tropical social wasp Ropalidia marginata and its dominance behavior in queen-less colonies of the prim- Berlin).

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