Figure 1.

Spatiotemporal parameters. Stride frequency, duty factor (d) and the term 1 + (d/(1 − d))² from Eq. (11) are plotted for chimpanzees (red circles; data from Pontzer et al.²) and humans (blue squares; data from Pavei et al.²⁹). Species-specific linear and polynomial regression equations are shown, together with their coefficient of determination (R²).