However, it should be noted that DCMS even has high power (>55%) in cases where none of the elementary statistics has a power >38% (for example, with selection coefficient 0.005 both in the divergent selection case).
In six of 12 alleles, selection was either positive or negative depending on the life stage in question – i.e. the direction of selection varied between life stages; for example, DAA*0901 had a selection coefficient of 0.24 in parr but −0.39 in migrants (Fig. 4).
More detailed results from two example simulations from the constant selection coefficient set (σ=0.1, U=1×10−7) are shown in Figure 2. In the first example (Fig. 2a d), the model marker frequencies are very close to those from the simulation (Fig. 2b).
For example, a genotype with a selection coefficient of 0.30 has 30% lower fitness than the most-fit genotype.
For example, we can use a likelihood ratio test with 1 df to determine whether the selection coefficient for a particular amino acid, for example, γPhe, differs significantly from zero, by comparing a reduced model with γPhe fixed at zero, denoted by L0(D |Θ, γPhe = 0), with the full model L0(D |Θ).
For example, a single locus with two alleles and time-independent selection coefficient f has α(f) = tanh(Nf) at evolutionary equilibrium (Kimura 1962; Mustonen and Lässig 2007).
For example, previous work by Kim and Stephan (1999) analyzed a single locus under a constant selection coefficient, using a diffusion approximation, and two recent simulation studies employed forward simulations with loci parameterized by constant selection coefficients to obtain power estimates (Baldwin-Brown et al. 2014; Kofler and Schlotterer 2014).
A selection coefficient of s = 10−3 and a mutation rate of 10−8 per site, for example, would require a locus of length 10 kb to achieve u/ s = 0.1.
The selection coefficient is a measure of the reduction in fitness of a genotype.
Our theory shows that the selection density (i.e., the selection coefficient per base pair) is a key parameter underlying this relationship.
