About the Authors

Cedric Puleston

puleston@ucdavis.edu

Affiliation Department of Anthropology, University of California Davis, Davis, California, United States of America

Shripad Tuljapurkar

Affiliation Department of Biology, Stanford University, Stanford, California, United States of America

Bruce Winterhalder

Affiliation Department of Anthropology, University of California Davis, Davis, California, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: CP ST BW. Performed the experiments: CP ST BW. Analyzed the data: CP ST BW. Wrote the paper: CP BW.