My research focuses on the evolution and development of bizarre, or extreme morphologies in insects. Beetles of the family Scarabaeidae exhibit extraordinary variation in male morphology. Males in many species have "horns", and these horns vary interspecifically in size and shape, as well as in the location on the animal from which they extend (e.g. some species have horns on the head, others have horns on the thorax). Research in my lab combines the tools and perspectives of behavioral ecology, quantitative genetics, evolutionary biology, phylogenetics and developmental biology to study beetle horn evolution. This explicitly integrative and multidisciplinary approach provides fresh insight to studies of sexual selection, and behavioral and morphological diversity. Graduate students in this lab often develop their own systems, and current student research addresses a breadth of topics revolving around sexual selection, behavior, genetics (direct and indirect) and evolution.
Specific projects include:
1. Sexual Selection and the evolution of exaggerated morphologies in insects (evolutionary radiation; diversity; animal behavior; alternative reproductive tactics; morphological evolution)
2. Integrative Developmental Biology of insects (mechanisms responsible for nutrient-dependent phenotypic plasticity, allometry, polyphenism, and sexual dimorphism)
3. Evolutionary Developmental Biology and the origin and adaptive evolution of complex traits (using insights from development to improve our resolution of historical patterns of evolution; candidate pathways and genes involved with the development and evolution of beetle horns).
4. Tradeoffs associated with production of beetle horns
5. Mystery of the Scarabs resolved? Starting to put the pieces together…
B.A. Cornell University, 1989
Ph.D. Princeton University, 1994
Simmons, L. W. and Emlen, D. J. Evolutionary trade-off between weapons and testes. Proceedings of the National Academy of Science (USA) (in revision).
Emlen, D. J. and Philips, T. K. (2006) Phylogenetic evidence for an association between tunneling behavior and the evolution of horns in dung beetles (Coleoptera: Scarabaeinae). Coleopterists Bulletin (in press).
Emlen, D. J., Szafran, Q., Corley, L.W. and Dworkin, I. Insulin signaling and limb-patterning: Candidate pathways for the origin and evolutionary diversification of beetle horns. Heredity 97: 179-191.
Emlen, D. J., Marangelo, J., Ball, B. and Cunningham, C. W. (2005) Diversity in the weapons of sexual selection: Horn evolution in the beetle genus Onthophagus (Coleoptera: Scarabaeidae). Evolution 59: 1060-1084.
Emlen, D. J., Hunt, J., and Simmons, L. W. (2005) Evolution of sexual dimorphism and male dimorphism in the expression of beetle horns: phylogenetic evidence for modularity, evolutionary lability, and constraint. American Naturalist 166: S42-S68. (Vice-President’s Symposium Issue).
Hartfelder, K. and Emlen, D. J. (2004) Endocrine control of insect polyphenism. Comprehensive Molecular Insect Science 3: 652-702.
Emlen, D. J. and Allen, C. E. (2004) Genotype to Phenotype: Physiological control of trait size and scaling in insects. Integrative and Comparative Biology 43: 617-634.
Ambrose, H.W.A. III., Ambrose, K. P., Emlen, D. J. and Bright, K. L. A (2004) Handbook of Biological Investigation, Sixth Edition. Hunter Textbooks Inc., Winston Salem, N.C. [link to Hunter Textbooks] http://www.huntertextbooks.com/biology.htm#research
Emlen, D. J. (2001) Costs and the diversification of exaggerated animal structures. Science 291: 1534-1536.