Rebecca Fisher
Research
My research focuses on the functional anatomy and evolution of mammals, including primates, artiodactyls, and carnivores. Current research projects include the analysis of the musculoskeletal system of hippos and red pandas. In addition to my dissection-based projects, I also conduct paleontological research on fossil hippos in Kenya.
Hippos are an interesting group to study, as they are the only semi-aquatic artiodactyls, and show marked adaptations for this unique lifestyle. There are two extant species, the common hippo (Hippopotamus amphibius) and the pygmy hippo (Choeropsis liberiensis). The phylogeny of this group is very contentious. Hippos were traditionally classified as Suiformes, a group that also includes pigs and peccaries. However, molecular data indicates hippos and cetaceans are sister taxa. In addition, many molecular analyses place ruminants as an outgroup to the hippo + cetacean clade, further distancing hippos from suids and tayassuids. In collaboration with colleagues, I dissect pygmy and common hippos in order to document the anatomy of these species. We analyze the functional and phylogenetic implications of the soft tissue characters observed in the lab. Data indicate that hippos do in fact share a number of features with ruminants; however, they are unique among artiodactyls in retaining a number of primitive muscles. These findings are consistent with the hypothesis that hippos diverged early in the history of Artiodactyla.
The phylogeny of the red panda (Ailurus fulgens) is also hotly contested. Red pandas are endangered carnivores living in the temperate forests of the Himalayas and southern China. Since the time of their initial description in 1821, their classification has been the subject of much debate. Morphological and molecular studies have supported a wide range of possible relationships, including close ties to procyonids, ursids, ursids + pinnipeds, and musteloids. The soft tissue anatomy of this species remains largely undocumented. In my lab, we are dissecting the musculoskeletal system of Ailurus in order to elucidate its functional anatomy and evolutionary relationships within Carnivora.
Selected Publications
Fisher, RE, Scott, K., and Naples, V. in review. Forelimb myology of the pygmy hippopotamus (Choeropsis liberiensis). Anat Rec Part A.
Fisher, RE, Hicks, M., and Elrod, C. 2006. Documenting the anatomy of an enigma: the hindlimb myology of Ailurus fulgens. J Vertebr Paleontol 26 (Supplement): 61-62.
Fisher, RE, Scott, K.M, and Naples, V.L. 2005. The comparative anatomy of the pygmy hippopotamus (Choeropsis liberiensis): appendicular myology. FASEB J 19 (No. 5, Pt. II): 776.7.
Fisher, RE. 2003. Variation in the extrinsic and intrinsic muscles of the fetal human foot. FASEB J 17 (No. 5, Pt. II): 470.6.
Fisher, RE. 2003. Fetus to Adult: The Development and Evolutionary Significance of Pedal Muscle Variation. Ph.D. Dissertation (December 2002), Yale University. (679 pp.)
Fisher, RE. 2000. The Primate Appendix: A Reassessment. Anat Record Part B 261: 228-236.