About the Authors
Institute of Biology, Leiden University, Leiden, The Netherlands
Instituto Gulbenkian de Ciência, Oeiras, Portugal
Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, California, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: PB ADL. Performed the experiments: PB ADL. Analyzed the data: PB SVS ADL. Contributed reagents/materials/analysis tools: PB SVS NP ADL. Wrote the paper: PB ADL. Provided the material for and assisted in mapping the visible markers: SVS. Prepared the butterfly material and identified the SNPs in candidate genes: NP.