About the Authors

Douglas J. Blackiston

Affiliation Department of Biology, Georgetown University, Washington, D. C., United States of America

Elena Silva Casey

Affiliation Department of Biology, Georgetown University, Washington, D. C., United States of America

Martha R. Weiss

To whom correspondence should be addressed. E-mail: weissm@georgetown.edu

Affiliation Department of Biology, Georgetown University, Washington, D. C., United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: DB MW. Performed the experiments: DB. Analyzed the data: DB. Contributed reagents/materials/analysis tools: DB ES MW. Wrote the paper: DB ES MW.