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An illustration of a Trilobite moving about on a Cambrian Period (400 million years ago) sea bottom. Trilobites are a well-known fossil group of extinct marine arthropods that form the class Trilobita.

Qbio Seminar Series: Prashant Sharma

Event Details

When: November 30, 2016, 2:00 PM

Location: 3rd Floor Orchard View Room , Discovery Building

Contact: 608-316-4401, hstampfli@wisc.edu

Prashant Sharma

Prashant Sharma
Assistant Professor
University of Wisconsin–Madison

Phylogenomics of ancient arthropods and integrating data classes in evolutionary inference

The phylogenetic position of Scorpiones and the attendant evolutionary scenario of arachnid terrestrialization have a long and contentious history. The datasets of morphologists and paleontologists typically recover scorpions at or close to the base of the arachnid tree of life, whereas molecular sequence data have recovered support for a clade comprised of scorpions and tetrapulmonates (groups united by a respiratory organ called the book lung). To adjudicate between these competing hypotheses with an independent data class, we examined both traditional phylogenomic datasets, as well as the structure and composition of euchelicerate genomes, using mandibulate genomes as a point of reference. Here we show that phylogenomic analyses with over 3,600 genes support the sister group relationship of scorpions and tetrapulmonates. In addition, the architecture of chelicerate genomes and gene expression surveys, support this relationship as well. Taken together, these data suggest a single, derived origin of the arachnid book lung and transform previous scenarios of the evolution of terrestrialization in Arachnida

All QBio sponsored talks take place on Wednesdays at 2:00 p.m. in the 3rd floor Orchard View room of the Discovery Building unless otherwise noted. Talks are open to the public. Access to the room is via the elevator behind Aldo’s Cafe in the Northeast corner of the building.