Figure A2.

Time intervals generated from concavity in the mapping from calendar to biological time, induced by decreasing the speed of the biological clock for time intervals further into the future (γ = 0.5). The biological clock does not exhibit autocorrelation (ρ = 0). The discounting curve in biological time is exponential with discount rate equal to 1. The dasheddotted line depicts the resulting discounting curve in calendar time (“Concav”). The best exponential (“Exp”) fit in calendar time produces a discount rate of 0.40, and the best hyperbolic fit (“Hyp”) has a discount rate equal to 2.20.