Placing Ratfish in the “Tree of Life”

Figuring out the evolutionary relationships of ratfish is the impetus behind a $52,349 National Science Foundation (NSF) grant that Millersville University of Pennsylvania biology professor, Dr. Dominique Dagit, recently received.  Dagit’s work will contribute to the larger NSF “Tree of Life” project, which aims to construct a phylogeny — lines of descent — for the 1.7 million described species of life.

“This project can help answer questions and provide advances in many areas,” said Dagit. “This sort of research has proven useful in many fields, such as choosing experimental systems for biological research, tracking the origin and spread of emerging diseases, creating pharmaceutical and agrochemical products, targeting biological control of invasive species, and evaluating risk factors for species conservation and ecosystem restoration.”

Dagit’s work will be part of a multi-million-dollar global project aimed at understanding the evolutionary relationships of all Chondrichthyans, which includes not only ratfish, but also sharks, rays and chimaeras. The Chondrichthyan piece will then contribute to the overall Tree of Life program.

“Despite being an ancient group, we know surprisingly little about the patterns and processes that gave rise to the current diversity of Chondrichthyans,” said Dagit.  “And, it’s a diversity that is increasingly under threat through environmental and fishing pressures.”

The research on ratfish over the next three years will take Dagit to Iowa State University, New York and Paris.

This project will catalog the diversity of these marine animals, provide a genealogy of relationships based on DNA sequence comparisons and provide a database of 3-D skeletons.

“It’s very inspiring to get to work with people around the world, using the latest in new technology,” said Dagit.  “To look at a ratfish via a 3-D CAT scan will provide a unique look at the specimens.  It’s a whole new way to look at ratfish and see the data and detail and how it fits into the larger picture.”

Dagit has been conducting research on ratfish since her senior thesis in college and she is the only person in the world currently researching ratfish diversity and evolution.