The influence of senescent mortality on the relationship between and <i>e</i>₀ (in years) when overall mortality rates are bathtub-shaped.

<p>Shown are data points calculated from mortality trajectories where <i>a</i>₀ = 0.5, <i>a</i>₁ = 0.778, and <i>c</i> = 0. (a) The effect of the level of senescent mortality (<i>b</i>₀). (b) The effect of the rate of senescent mortality (<i>b</i>₁).