Table 4. Parameter estimates for the best model.

Population	α	λ	ω
A	4.73	2.57E-06	0.106 (0.102 to 0.110)
Bear	3.93	9.45E-06	0.096 (0.092 to 0.100)
C	4.33	3.61E-06	0.095 (0.092 to 0.099)
Hansen	4.55	1.03E-05	0.126 (0.121 to 0.131)
Pick	5.50	5.48E-08	0.076 (0.074 to 0.079)
Yako	5.05	1.12E-06	0.104 (0.100 to 0.108)

Parameter estimates for α, λ, and ω (95% confidence bounds in parentheses based on likelihood profiles, [42]) derived from the best model (i.e., model VII, Table 3) for explaining senescence variation. The α parameter represents the shape of the Weibull hazard function, λ represents the magnitude of the Weibull hazard given the shape of the function, and ω is a derived parameter that provides a shape-adjusted index of the rate of senescence [26].