Fig 4. Predicted skill level at energy extraction throughout ontogeny plateaus in adulthood.

Lines are the predicted skill level vs age with (A) power and (B) exponential competence for the results in Fig 3. Circles are the observed cumulative distribution of self-reported acquisition ages of food production skills in female Tsimane horticulturalists [81] multiplied by our ${\widehat{x}}_{\mathrm{k}}$. However, note that the observed skills in Tsimane involve cumulative social learning which we do not model explicitly.