OEB Seminar Series: Prashant Sharma

Prashant Sharma
Associate Professor
University of Wisconsin, Madison

Reciprocal illumination between genomes, phylogeny, and development in the evolutionary biology of the arachnids

Abstract: Arachnids comprise a species-rich group of predatory arthropods that are found in ecosystems spanning most of the Phanerozoic. The discovery of a shared and ancient genome duplication (WGD) event in a subset of arachnid orders (the Arachnopulmonata) has dramatically changed modern understanding of arachnid phylogeny, as well as positioned this clade as a useful system to study the impact of new genes on diversification dynamics. However, much of the higher-level phylogeny of Arachnida remains unresolved, including the central question of whether horseshoe crabs are nested within the arachnids. In addition, the relationship between morphological innovations of  arachnopulmonates (e.g., spider spinnerets; scorpion and spider venom glands) and functional diversification of duplicated genes stemming from their shared WGD is not understood. Here, I review advances in phylogenomic relationships of arachnids, focusing on insights resulting from analysis of rare genomic changes. I also critically examine the postulate that neofunctionalization of duplicated gene copies underlies the asymmetrical species richness of arachnopulmonate orders such as spiders.

Host: Professor Gonzalo Giribet