Shannon Corrigan

I'm fascinated by the natural history and evolution of marine organisms. My broad research interests include evolutionary ecology, biogeography and conservation biology, particularly of cartilaginous fishes. Previously, I’ve studied wobbegong sharks (Orectolobidae) and shortfin makos (Isurus oxyrinchus). I’m currently working on the molecular component of the CTOL project. We’ve developed new molecular tools that allow us to simultaneously target and sequence more than 1000 genes across divergent species of sharks, skates, rays and chimaeras. We use this data to investigate their species interrelationships. I feel very privileged to be involved in the CTOL project because I've had the opportunity to learn new and extremely powerful molecular techniques and am now able to explore interesting questions across the diversity of Chondrichthyan fishes. I'm excited to share this information with scientists and the general public via the project website. As a female scientist, I'm also hopeful that that this work may serve as encouragement for girls and women that are interested in pursuing a career in STEM fields.

Gavin Naylor

I'm an evolutionary biologist with a long standing interest in the evolution of vertebrate animals. Chondrichthyan fishes (sharks, skates, rays and chimaeras) are the modern day remnants of one of the oldest splits in vertebrate history. They branched off from the rest of jawed vertebrates about 425 million years ago and have persisted to the present day. Given their remarkable evolutionary persistence, it is quite surprising that these animals remain so poorly explored. They are much more diverse than is generally recognized. They are not “invariant relicts” of our ancient past, but rather are highly specialized well-adapted, modern organisms that exhibit anatomical and physiological adaptations to several different environments. We are interested in reconstructing the sequence of events that lead to the current diversity of chondrichthyan fishes. We’d like to understand how and when they acquired the novel traits they exhibit, the likely environmental forces that shaped their adaptations, and the biogeographic influences that have lead to their current distributions. All of this hinges on our having an accurate estimate of their phylogenetic relationships. In our research group we work with DNA sequence data and invest a lot of effort in trying to make sure our inferred phylogenies are correct. We sequence DNA from both the nuclear and mitochondrial genomes. We have developed new cross-species gene capture methods that allow us to collect data from several hundred orthologous protein-coding genes across divergent taxa. Over the course of 30 years, with extensive help from a number of international colleagues, we have been able to amass DNA samples from approximately 800 of the 1200 described living species of Chondrichthyan fishes. We hope to provide an accurate, temporally calibrated, highly resolved history of the evolutionary diversification of all sharks, skates, rays and chimaeras.



Lei Yang

I’m interested in the systematics, biogeography, evolution, and conservation of both freshwater and marine fishes. For my Masters research I studied the phylogeography of two bagrid catfishes. I then began working with Dr. Richard Mayden on the tree of life of the cypriniforme subfamily Cyprininae (carps, goldfishes etc.), which is the largest polyploid lineage of all fishes. I joined the Naylor Lab in 2013 as a postdoctoral researcher on the CTOL project where my main work is to investigate the phylogenetic relationships, biogeography, and evolution of skates and rays. I’ve also optimized a gene capture target enrichment method that allows us to efficiently collect whole mitochondrial genome sequences for chondrichthyes. I am currently estimating the time of origin and divergence of all lineages of chondrichthyan fishes using the genetic data we collected and the fossil records. The information will be mapped on the tree of our website to provide a timescale for the evolution of these amazing animals.