Table 2.

Estimation of the Fitness Cost of a Mono-SSR of 8 Units

	Model 1 (Selection and Mutation)	Model 2 (Selection, Mutation, and Drift)
h	s × 10−7	α	s × 10−7
0	58.2 (89.1)	—	—
0.1	12.6 (19.4)	3.3 (4.4)	1,645.7 (2,216.0)
0.5	3.1 (4.7)	0.7 (0.9)	329.1 (443.2)
1	1.6 (2.4)	0.3 (0.4)	164.6 (221.6)

Note.—In the first model (fig. 1, left), the population size is assumed to be infinite. In this case, drift is neglected and the selection coefficient s is computed using equation 1. In the second model (fig. 1, right), population size is finite and α = 2N_es is computed under equilibrium between selection, mutation, and drift using equation 2. Numbers in regular typeface are given assuming a JC mutational model; numbers in parentheses are computed assuming a K2p mutational model. The following values were used in the equations: c = (1 + 2/8)/3 for the JC model and c = (1 + 2/8)[0.47 × 6/(6 + 2) + (1 − 0.47)/(8 + 2)] for K2p model, d = 8, µ = 2 × 10⁻⁸, P = 0.026, N_e = 10⁴.