I am interested in the evolutionary responses of rodents to both catastrophic and gradual environmental changes. My research includes investigating patterns of change in an extinct group of Eocene rodents of the family Ischyromyidae. Ischyromyids are the first rodents to show up in the fossil record, Late Paleocene-Early Eocene (around 55-54 my). They diversified quickly, changed slowly in morphology, and then became extinct in a relatively short time period. This pattern is similar to that found in more recent organisms and may be one of many consequences of a global warming trend.Rodents of the family Ischyromyidae first evolved during a period of documented global change, the Paleocene-Eocene warming trend. Their fossil record reveals an increase in diversity near the end of this warming trend followed by an increase in size as temperatures cooled during Eocene time. The ischyromyids were particularly abundant and diverse through the Middle Eocene (about 48 my), surviving periods of environmental cooling and drying. Studying patterns of change such as this, leads to insight about how today's organisms may respond to future climatic changes.
Anderson, D. K. 2008. Family Ischyromyidae. In: Evolution of Tertiary Mammals of North America, Volume II. Eds. Christine M. Janis, and Gregg F. Gunnell, and Mark Uhen.
Anderson, D. K., J. Damuth, and Bown, T. M. 1995. Rapid morphological change in Miocene rodents and marsupials associated with a volcanic catastrophe in Argentina. Journal of Vertebrate Paleontology 15(3): 640-649.
Anderson, D. K. 1993. A method for recognizing morphological stasis. Proceedings of the Morphological Change in Pleistocene Mammals Symposium. Cambridge University Press.