DISSERTATION RESEARCH: The role of biotic association in the evolution of a megadiverse marine bivalve clade

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

The enormous biodiversity on earth not only provides humans valuable biological resources, but also serves as a crucial component of our highly interdependent ecosystem. How this great biodiversity is generated remains a central question of biology. While much of the tree of life can be generated through abiotic (non-living) processes, such as climate change or tectonic movements, some of the most striking diversities arise from biotic interactions between species. Evolutionary studies of contemporary marine lineages are typically framed within abiotic hypothesis-testing contexts and have collectively lagged behind terrestrial studies in developing an integrated framework that includes a meaningful biotic perspective. The proposed research addresses this deficiency by studying the evolution of the hyperdiverse clam group Galeommatoidea. It is a particularly apt group because it contains large numbers of free-living as well as symbiotic (living with a host) species and is therefore amenable to comparative approaches. The evolutionary pathways of both free-living and symbiotic clams are affected by abiotic factors, but the symbiotic species are influenced by an additional biotic factor: their ecological interactions with hosts. By comparing the evolutionary patterns of the two groups, the relative roles of abiotic and biotic factors in driving the diversification of this species-rich marine lineage can be assessed. The proposed research complements the NSF-funded ?Assembling the Bivalve Tree of Life? initiative and involves extensive collaboration with national and international museum collections. One graduate student is receiving in-depth research training in phylogenetic, morphological and macroevolutionary analysis. Four undergraduate students have been receiving training in molecular phylogenetic techniques. Many specimens involved in the project will be deposited into the Museum of Zoology, Ecology and Evolutionary Biology, University of Michigan. The graduate student and two other undergraduate students will be trained to computerize museum collections and manage electronic taxonomic databases. In addition, biodiversity data of selected galeommatoidean clams will be contributing to the Animal Diversity Web (ADW), a premier source of public biodiversity information that also directly feeds into the online Encyclopedia of Life. The ADW also serves as a free biodiversity database that allows students/researchers to conduct comparative meta-analysis across the tree of life.