About the Authors

E. Penelope Holland

Affiliations Central Science Laboratory, Sand Hutton, York, United Kingdom , Department of Biology, University of York, York, United Kingdom

James N Aegerter

To whom correspondence should be addressed. E-mail: j.aegerter@csl.gov.uk

Affiliation Central Science Laboratory, Sand Hutton, York, United Kingdom

Calvin Dytham

Affiliations Department of Biology, University of York, York, United Kingdom , Plant Ecology and Nature Conservation, University of Potsdam, Potsdam, Germany

Graham C Smith

Affiliation Central Science Laboratory, Sand Hutton, York, United Kingdom

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

EPH, JNA, and GCS conceived and designed the experiments. EPH performed the experiments and supplied reagents/materials/analysis tools. EPH and CD analyzed the data. EPH and JNA wrote the paper.