• Ph. D. Evolutionary Biology, 1998, University of Chicago
• M. Arch. (Architecture), 1983, Harvard University
• B. S. Architectural Studies, 1979, University of Illinois

My interest is in the developmental sources of morphological differences between animal groups. The material for morphological change is variation in developmental patterns. This variation is filtered through the sieve of natural selection, and other genetic evolutionary processes, to result in the animal forms we find today. My work is the study of developmental variation at the level of regulation of gene expression.

Current studies are focused on examining the extent and nature of variation in genomic regulatory elements. The research employs a variety of techniques to determine gene expression patterns and functionally test genomic regulatory DNA for its role in controlling those expression patterns. The principle study organisms are ascidians, which have a number of experimental advantages for this work, especially for transgenic reporter assays. The data are analyzed in a phylogenetic context both within ascidians and in relation to data from other chordates. The long term goal of these studies is to apply increasingly fine levels of comparative analysis to trace evolutionary patterns in regulatory DNA.

Past research and future plans include a range of taxa. The study groups are chosen based on the evolutionary question involved. While current work is on genomic regulation, my interests extend throughout the field of evolutionary developmental biology.

• Irvine S.Q., Carr J.L., Shimizu N., Bailey W., Amemiya C.A., Ruddle F.H. 2001. Genomic analysis of Hox clusters in the sea lamprey Petromyzon marinus. In review.


• Irvine S.Q., Martindale M.Q. 2001. Comparative analysis of Hox gene expression patterns in the polychaete Chaetopterus: implications for the evolution of body plan regionalization. Am. Zool. 41:640-651.


• Irvine, S.Q. and Martindale, M.Q. 2000. Expression patterns of anterior Hox genes in the polychaete Chaetopterus: Correlation with morphological boundaries. Dev. Biol. 217:333-351.


• Irvine, S.Q., Chaga, O. and Martindale, M.Q. 1999. Larval ontogenetic stages of Chaetopterus: Developmental heterochrony in the evolution of chaetopterid polychaetes. Biol. Bull. 197:319-331.


• Panganiban, G., Irvine, S.M., Lowe, C., Roehl, H., Corley, L.S., Sherbon, B., Grenier, J.K., Fallon, J.F., Kimble, J., Walker, M., Wray, G.A., Swalla, B.J., Martindale, M.Q. and Carroll, S.B. 1997. The origin and evolution of animal appendages. Proc. Natl. Acad. Sci .USA 94:5162-5166. (SMI is co-first author).


• Irvine S.M., Warriner, S., Hunter, J. and Martindale, M.Q. 1997. A survey of homeobox genes in Chaetopterus variopedatus and analysis of polychaete homeodomains. Mol. Phylogen. Evol. 7:331-345.