Candidate models for explaining inter-population variation in senescence.

For each model, the shape-adjusted index of the rate of senescence (��) was regressed against the factors listed under the general model structure. In each case, the betas represent the estimated parameters (��0 represents the intercept coefficient and �� 1, �� 2, and �� 3 represent slope coefficients). We have also listed the negative log-likelihood (NLL), the number of parameters (No. parameters), Akaike's Information Criterion (AIC), and the ��AIC (relative to the best model, model 7).