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SCIENCE AT THE EDGE SEMINAR
QB/GEDD
Friday, August 29 at 11:30am
Room 1400 Biomedical and Physical Sciences Bldg.
Refreshments at 11:15
Mark Rebeiz
Department of Biological Sciences
University of Pittsburgh
Morphological Evolution: The Modification and Origination of Nodes and Networks in Development
One of the major quests in biology is to understand how the spectacular diversity of animal forms that exist on our planet evolved. Merging the study of embryonic development with evolutionary biology, the field of “evo-devo” seeks to find
genes and mutations that contribute to differences in anatomy.Early work in this field revealed how the vastly different creatures of the animal kingdom are built using a similar set of body patterning genes, suggesting that form largely evolves by changing
how genes are patterned during development. Gene expression is controlled in time and space by transcriptional switches, stretches of DNA that bind combinations of transcription factors to activate the gene. A multitude of empirical examples have illustrated
how the evolutionary modification of switches contributes to phenotypic differences between species.
Research in the Rebeiz lab is focused on how regulatory switch evolution participates in the generation of novelty. How do completely new structures such as the turtle’s shell or a bird’s feather evolve? At the root of this problem lies
the question of how new transcriptional switches and developmental networks composed of multiple switches come into being. Using closely related species of Drosophila as a model, Dr. Rebeiz has been studying switches that were very recently born. By tracing
the origins of recently evolved gene expression patterns, Dr. Rebeiz’s research has found that new switches may tend to evolve on top of pre-existing switches. Expanding this view from a single switch to a developmental network of switches, Rebeiz will discuss
ongoing research investigating the developmental basis of recently derived anatomical structures in Drosophila.