Intellectual merit

Annelids comprise >16000 recognized species that occupy a wide range of marine, freshwater and terrestrial environments. Many members of this ancient group are ecologically and economically important as ecosystem engineers, as the basis of commercial enterprises, as indicators of environmental health, as invasive or pest species and as being arguably the most abundant metazoans in the deep sea, which covers 60% of the planet. As one of the few segmented phyla, annelids are key to understanding the evolution of bilaterian body plans. During the course of this award, we have used cutting-edge genomic technologies to discover and understand the evolutionary history of this important group. Analyses conducted with the genomic data have made clear that annelids are a much more diverse group than previously recognized and they contain several worm-like groups formerly recognized as separate animal phyla. We also place the fresh water and terrestrial annelids (clitellates) with specific groups of sedentary polychaetous worms. Also lineages that branched off from early near the base of the annelid tree, appear to have been much more complex than traditionally understood. This work has produced a large number of genetic resources that are being used to explore the evolution of key gene families across the annelids, mollusks and similar phyla. Using this information, we have achieved the main goal of this award which was to reconstruct a robust evolutionary tree of annelids - the sixth most species rich animal phylum.

We also conducted several studies that were taxonomically focused on specific groups. For example, we examined the evolution and blood pigments of siboglinid worms which live in chemosynthetic environments. Also we assessed the biogeography and population genetics of specific species, including Platynereis dumerilii which is a model system for development. Such studies help us understand the breadth and variation of these animals.

Another major aspect of this work was development of bioinformatic pipelines and tools which aided the reconstruction of the annelid tree and allowed analyses of genomic data. These tools have since been applied to other organismal groups and are helping establish standard protocols for evaluation of phylogenomic data.

Broader Impacts

Our results will have significant implications for multiple fields, such as developmental biology, paleontology, physiology, and evolution. Specimens,  data, and other resources have been made publicly available, and results have been published in high-impact, peer-reviewed journals. Additionally, we conducted numerous outreach activities, for K-8 students (roughly 300 students per year), teachers, and the general public, that improve appreciation of annelid diversity and the significance of evolutionary analyses in understanding the diversity of life. Other major impacts of the project include the training of undergraduate (>5) and graduate students (>5) and a postdoc at Auburn University. This work also included international collaborative efforts with researchers in Germany, Brazil, Norway, Australia and South Africa. Such international collaboration promotes intellectual interchange and helps students prepare for future collegial interactions. Throughout the project, underrepresented groups have participated.

Last Modified: 03/31/2017
Modified by: Kenneth M Halanych