H. Kern Reeve
Section of Neurobiology and Behavior
Seeley G. Mudd Hall
Cornell University
Ithaca, New York 14853
hkr1@cornell.edu
The general goals of my research are to understand the principles governing the evolution of animal societies and, especially, to investigate the evolutionary causes and consequences of cooperation and conflict within these societies.
My current research focuses on the problem of how the members of an animal society resolve potential conflicts over how to divide up overall group reproduction. In particular, I have extended and tested models predicting the conditions under which a dominant member of a society should concede reproduction to a subordinate member as an incentive for the subordinate to stay in the group and help the dominant. To test these "transactional" models of reproductive partitioning (known also as "optimal skew" and "concessions" models), I have examined whether naturally co-nesting social wasp queens divide up reproduction according to relatedness, fighting ability, and ecological factors in the ways predicted by the models. Current evidence suggests that the social contract models may apply widely to animal societies.
My ultimate aim for this line of research is to develop a rigorous, empirically well-tested, general theory of the fundamental properties of animal societies as a function of colony genetic structure, relative fighting abilities of colony members, benefits of colony cooperation and opportunities for solitary reproduction. If the transactional models continue to prove correct, for the first time it will be possible to predict quantitatively multiple, complex properties of both natural and manipulated social systems with advance knowledge of only a few key social parameters.
Finally, a second major goal of my research is to develop a comprehensive theory of the link between the sex chromosome organization of a species and its tendency to evolve complex sex-limited phenotypes such as parental or alloparental care. This theory, which I term protected invasion theory, focuses on the likelihood that a rare, favored allele promoting parental or alloparental care will survive loss from the population due to random genetic drift. It may be the best general explanation for observed correlations between chromosome system and pattern of parental or alloparental care. For example, it explains the prevalence of eusociality and female-biased workers in the Hymenoptera (ants, bees, and wasps), the biases toward male helpers in avian and female helpers in mammalian cooperatively breeding societies, the bias toward female cooperators in social spiders, and the lack of such sex biases in termites.
I plan to further test this theory by examining the association between sex chromosome systems and patterns of parental care in fish and amphibia, both of which exhibit highly variable sex biases in parental care. In sum, both I plan to further test both social contract theory and protected invasion theory as complementary, unifying general theories of social evolution.
For more information, see:
http://www.bio.cornell.edu/neurobio/reeve/reeveworks.html
The following is a list of references that are relevant to my research interests:
Reeve, H. K., J. Peters, P. Nonacs, and Starks, P. 1998. Early "worker" dispersal in social wasps: causes and implications of an alternative reproductive strategy. Proceedings of the National Academy of Sciences (USA). 95: 13737-13742.
Reeve, H. K., Emlen, S. T. and L. Keller. 1998. Reproductive sharing in animal societies: reproductive incentives or incomplete reproductive control by dominant breeders? Behavioral Ecology. 9: 267-278.
Reeve, H. K. and J. S. Shellman-Reeve. 1997. The general protected invasion theory: sex biases in parental and alloparental care. Evolutionary Ecology. 11: 357-370.
Reeve, H. K. and L. Keller. 1997. Reproductive bribing and policing as mechanisms for the suppression of within-group selfishness. American Naturalist (special issue on "Multi-level Selection").150: S42-S58.
Reeve, H. K. and Keller, L. 1995. Partitioning of reproduction in animal societies: mother-daughter versus sibling associations. The American Naturalist. 145: 119-132.
Reeve, H. K. 1993. Haplodiploidy, eusociality, and the absence of male parental and alloparental care in the Hymenoptera: a unifying genetic hypothesis distinct from kin selection theory. Philosophical Transactions of the Royal Society (Lond.), Series B. 342: 335-352.
Reeve, H. K. 1992. Queen activation of lazy workers in colonies of the eusocial naked mole-rat. Nature. 358: 147-149.
Reeve, H. K. and P. Nonacs. 1992. Social contracts in wasp societies. Nature