About the Authors

Boris H. Kramer

kramer@demogr.mpg.de

Affiliation Laboratory of Evolutionary Biodemography, Max Planck Institute for Demographic Research, Rostock, Mecklenburg-West Pomerania, Germany

Ralf Schaible

Affiliation Laboratory of Evolutionary Biodemography, Max Planck Institute for Demographic Research, Rostock, Mecklenburg-West Pomerania, Germany

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: BHK. Performed the experiments: BHK. Analyzed the data: BHK. Contributed reagents/materials/analysis tools: BHK RS. Wrote the paper: BHK RS.