The rockefeller university

by BRETT NORMAN

Daniel Kronauer, who will join Rockefeller in July 2011 as head of the Laboratory of Insect Social Evolution, is interested in understanding how evolution operates at different levels of organization in the rich context of insect societies, from the gene to the individual and society as a whole.

Insect societies are often integrated to such a degree that they are conceptualized as “superorganisms,” where individuals are morphologically and behaviorally differentiated into castes with different functions, analogous to different tissues in conventional organisms. Dr. Kronauer uses an integrative approach combining genomics and transcriptomics, population genetics, molecular phylogenetics, chemical ecology, laboratory-based behavioral experiments and fieldwork to explore how natural selection has shaped these social systems at different hierarchical levels.

“The study of social insects brings an extra layer to the understanding of evolution,” says Dr. Kronauer. “It adds the dimension of the society. As the societies get more and more complex, you have to understand how these different hierarchical levels are interacting with one another. Cooperation has to be maintained, and conflicts have to be resolved or suppressed, and understanding that is one of my major interests.”

In the lab, Dr. Kronauer primarily works with Cerapachys biroi, an ant species that is attractive as an experimental system because its populations exhibit the interesting social behavior of army ants but reproduce asexually, providing control over the genetic background. Dr. Kronauer will sequence the genome and transcriptome of the species to establish this ant as a model system in which he can study behaviors such as reproduction and foraging.

Dr. Kronauer also studies nomadic species of army ants in the field, ranging from Kenya to the New World tropics of Venezuela, where he tracks colonies, some of which move as much as 100 meters each night. Previous work has shown that army ant colonies have very complex pedigree structures and an idiosyncratic way of reproducing by fission. He hopes to understand how and why this system has evolved and how it has shaped altruistic worker behavior and social conflicts in evolutionary terms. He is also interested in the evolution of morphological and behavioral worker castes, particularly in response to ecological changes, as well as ant symbionts including microbes and arthropods.

Dr. Kronauer, who is originally from Germany, received his Ph.D. at the University of Copenhagen in 2007 and was a postdoc there as well as at the University of Lausanne before joining Harvard University as a junior fellow in July 2008. He was the first to develop and use population genetic markers for a broad range of army ant species, and his research showed that many of the most complex insect societies, like those of army ants, rely on high genetic diversity. In army ants this is typically achieved by single queens that mate with an extraordinary number of males, a finding Dr. Kronauer published in 2007 in Evolution, or, in one special case, by colonies that host multiple queens, published the same year in Current Biology
Dr. Kronauer also is an avid nature photographer, shooting ants in the field. His close-up images of ants have appeared on the covers of journals such asCurrent Biology, Evolution and The Journal of Evolutionary Biology. “It’s a hobby, a nice complement to the scientific work I’m doing. It’s a way to access the world of the ants and discover things you couldn’t see with your eyes alone.”