Parting Genomes: University Of Arizona Biologists Discover Seeds Of Speciation

A University of Arizona graduate student may be the first eyewitness to the birth of a new species. Her new findings, appearing in the June 7, 2004 Proceedings of the National Academy of Science, could help biologists identify and understand the precise genetic changes that lead a species to evolve into two separate species. Laura K. Reed and her advisor, Regents’ Professor Therese Markow, made the discovery by observing breeding patterns of fruitflies that live among rotting cacti in western deserts. Whether the two closely related fruitfly populations, designated Drosophila mojavensis and Drosophila arizonae, represent one species or two is still debatable among biologists, testament to the Arizona researchers’ assertion that they are in the early stages of diverging into separate species.