Brown CS News

Evolution, Software, and Microinversions

    Biologists will be able to reconstruct the process of evolution, determine relationships between species and build phylogenetic trees with greater accuracy thanks to a new method for identifying “microinversions,” which are extremely short strings of inverted nucleotides. This new work from researchers at UC San Diego and Brown University appeared in the online edition of the Proceedings of the National Academy of Sciences (PNAS).

    "Three years ago, we didn't know microinversions existed," explained Pavel Pevzner, the senior author on the paper, a computer science and engineering professor at UCSD's Jacobs School of Engineering, and director of the newly-established Center for Algorithmic and Systems Biology (CASB) at the UCSD Division of Calit2. "When they were discovered, there was a lot of skepticism. In the last year, scientists have discovered just how common microinversions are in evolution -- even in variation between humans, which is why they are such a hot topic today."

    "This microinversion detection method could be used for detecting human structural variants once we have the necessary data," explained Ben Raphael, a former postdoc in Pevzner's lab and now a professor of computer science at Brown University. Raphael is the second author on this paper and a former postdoctoral researcher at UCSD. Raphael helped establish CASB and is organizing the RECOMB Satellite Workshop on Computational Cancer Biology at Calit2 next September 16-18, 2007.

    With microinversions, researchers are not limited to comparing species that are evolutionarily close, as is the case when using other genomic features like repetitive sequences and deletions for phylogenetic analysis. The new process can also detect microinversions that are the result of convergent evolution and thus do not play a role in tracking evolution and defining phylogenies.

    To read more, visit