URI Researcher Helping to Build Tree of Life

By ecoRI News staff

KINGSTON, R.I. — A University of Rhode Island biologist has been awarded a $2.5 million grant from the National Science Foundation (NSF) to study the genetics of three groups of parasites and single-celled organisms, to help scientists complete a detailed tree of life of Earth’s living organisms.

The grant to Christopher Lane, associate professor of biological sciences, is part of NSF’s Genealogy of Life program, which is examining the evolutionary patterns and processes of life on Earth.

“There are lots of areas of the tree of life that we know very little about,” said Lane, who joined the URI faculty in 2008 and studies marine biodiversity and comparative genomics. “We don’t know a lot about what’s at the base of the tree of life, for instance, and what major groups belong together. To figure that out, we’ve got to collect more data from areas of the tree that we don’t understand well.”

Lane, his students, and colleagues at the University of Maryland and Smith College, will focus their work on the stramenopiles, which include diatoms, brown algae and water molds; the rhizaria, single-celled marine and aquatic organisms that serve as decomposers and predators on the micro scale; and the alveolata, a group of more than 6,000 single-celled parasites, ciliates and dinoflagellates.

“These three groups are responsible for an enormous amount of ecosystem functioning that we don’t appreciate or fully recognize,” Lane said. “Many are having huge impacts on food webs, both marine and terrestrial, and we know very little about what they do and who they are. Our job will be to get a whole bunch of genetic information from these organisms ... and understand their role in the ecosystem.”

The researchers will examine organisms in existing databases and collect new samples from freshwater, saltwater and terrestrial sites from a wide variety of habitats around the world. They will then sequence a short region of DNA from each member of the organisms they are targeting.

“That will give us an idea of what’s there or what the diversity is of those different groups in those environments,” said Lane, a resident of North Kingstown. “From that we’ll be able to tell which environments we need to explore more.”

According to Lane, gaps in the tree of life may create biases in the data that scientists use to understand the evolutionary relationships among species. A great deal more is known about plants and animals, for instance, than most other species groups, resulting in an over-representation of plants and animals in data sets.

“We’re trying to understand our living world and the evolution of organisms through time,” he said. “But there have been some significant changes in the past 15 years that completely change how we understand the evolution of some traits.

“And major groups of organisms we never knew existed have just shown up on our radar. We know them by their genetic signature, but we don’t know what they look like or what they consume.”

The five-year research project will result in the creation of about 250 draft genomes, thousands of new DNA barcodes and numerous images of organisms that will be deposited in online databases for scientists to use in future studies, including predictive modeling of the future evolution of life on Earth.