About the Authors
MRC Functional Genetics Unit, Department of Human Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
Department of Statistics, Bioinformatics Group, University of Oxford, Oxford, United Kingdom
The authors have declared that no competing interests exist.
GL conceived and designed the experiments, performed the experiments, and analyzed the data. GL, CPP, and JH contributed to ongoing discussions on molecular evolution and comparative genomics. GL and CPP wrote the paper.