Ant colonies have a striking division of labor: queens lay eggs, while workers, unable to reproduce, perform tasks such as brood care, foraging and defense. The task a worker performs depends on its size, age and experience. How is task performance in ants controlled by a tiny amount of nerve tissue, the brain? The goal of the project is to discover how differences in the brains of worker ants in a colony control task performance, and how the ecology of a species may influence worker brain structure and behavior. Ants may change tasks as they age, beginning as nurses and ending as foragers. Their brains need to be plastic so that they can generate age-appropriate behavior. In some species, workers show specialized behaviors, such as defending the colony, and are equipped with large and powerful jaws that make them effective soldiers. If workers are specialized for defense, their brains must respond to stimuli associated with threats to the colony and control aggressive behavior. Thus the brain of a nurse should respond only to the needs of brood and the brain of a defender should respond to threats from enemies. The project will analyze ant social behavior and examine age- and task-specific differences in the size of worker brains, brain compartments and individual nerve cells as well as the chemical composition of the brains of workers of different species in an extremely diverse group of ants. The expected subtle brain differences will help to understand how slight changes in brain structure and function can result in pronounced behavioral differences and how behavior develops during maturation. The project will train graduate and undergraduate students (including minority students) in behavioral, anatomical, neurobiological and molecular techniques and enrich the education of K-12 students by introducing them to behavior, neuroscience, ecology and evolution.
National Science Foundation funding enabled us to address critical and current questions at the intersection of animal social behavior and neuroscience. This work has generated new information on how the brains of individuals reflect adaptation to living in a complex society. The results of our research projects are not specific to the ants we use as models to understand the relationship between social life and brain size and structure. Indeed, our work helps us understanding how living in a complex society may affect brain evolution in other animal groups, including humans. Our work also may inform the design of biologically inspired robotic systems that rely on "swarm intelligence." Our research and science instruction accentuate critical thinking for students in all academic majors and at all levels, and thus foster the broad development of human resources. We train freshmen as well as doctoral degree candidates. Working in our lab, students master molecular, behavioral and neurobiological methods; they learn to dissect minute brains and measure their structure at the level of the whole brain, brain cells, and brain chemistry. They become adept at using sophisticated instruments in their analyses. Our undergraduate researchers are given the opportunity to become deeply involved in research, providing them with experiences that often change their career paths, and guide their development as scientists. Many of our undergraduate students, and all our graduate students, learn to prepare and publish scientific papers. Our research has been followed by national and international media outlets including the PBS, BBC, Science News and other journalistic venues. Our work has appeared in introductory textbooks as a model of experimental design. The vast majority of our lab members continue on to professional careers in science, education and medicine; many of our doctoral students become faculty at other institutions and carry their learning forward. We contribute to broad educational goals within our Department, College, University, and the Greater Boston community (such as the Upward Bound Program) by conducting interdisciplinary research in our institutional and outreach programs. This is accomplished in formal course work in which the linkage of the natural sciences, social sciences, and humanities is presented as the consilience approach to seeking knowledge. Our emphasis on integration of concepts and methods across disciplines is also evident in undergraduate and graduate research training, as well as outreach to underrepresented groups. Our lab is fully inclusive. We teach students from underrepresented groups and collaborate with high school teachers, faculty from natural science and social science departments, international faculty, librarians, artists and art institutions. The study animals we feature in our work – ants – are social insects that are intrinsically fascinating. The general public has a great familiarity with and long-standing appreciation for ants, and an interest in understanding the organization of their colonies and the behavior of workers acting alone or as members of collective groups. Ants are dominant in a number of biomes, and play prominent ecological roles in maintaining diversity. Ants are ecologically dominant life forms that deliver significant ecosystem services through their movement of soil and nutrients. They can be important predators that maintain diversity, significant agricultural and urban pests, as well as important agents of biological control. Our ability to control ants or harness their colonies for human benefits is predicated on a thorough understanding of their biology, which feature their social organization, one focus of our research. The knowledge we acquire from studies of the basic biology of ants can thus be applied to manage pest species in environmentally sensitive ways, and used to model the structure of behavioral efficiency through cooperation in all animal taxa. Ants are globally of great cultural significance, being preeminent in the mythologies of many societies. They are featured in the films Where the Green Ants Dream and Antz, and have appeared in numerous science fiction films, but have also appeared on the covers of major journals and Pulitzer Prize-winning books as icons of social complexity and cooperation. Our studies of the neurobiology of ant behavior and give novel insight into how social life is regulated by the brain and how intelligence is distributed across many individuals within a society, and in doing so extend our human fascination with and knowledge of ants as extraordinary superorganisms, as well as our understanding of the evolution of the brain.
