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Table 1 Models describing the distributions of clonal susceptibility for the pre-epidemic, post-epidemic and post-sex clones.

From: Parasite-mediated disruptive selection in a natural Daphnia population

Type of selection Model Pre-epidemic Post-epidemic Post-sex n AIC evidence ratio
No selection 1) unimodal: null μ A σ A μ A σ A μ A σ A 2 -45.29 2145
  2) bimodal: null μ 1A σ A μ 2A σ A μ 1A σ A μ 2A σ A μ 1A σ A μ 2A σ A 3 -51.61 90.8
Directional selection 3*) unimodal: mean, var differ μ A σ A μ B σ B μ C σ C 6 -44.74 2817
  4) unimodal: pre-epidemic differs μ A σ A μ B σ B μ B σ B 4 -47.99 557
  5*) bimodal: all modes differ μ 1A σ A μ 2A σ A μ 1B σ A μ 2B σ A μ 1C σ A μ 2C σ A 7 -56.96 6.27
  6) bimodal: pre-epidemic differs μ 1A σ A μ 2A σ A μ 1B σ A μ 2B σ A μ 1B σ A μ 2B σ A 5 -60.55 1.04
Disruptive selection 7) mixed: uni-bi.-bi., same modes μ A σ A μ 1B σ A μ 2B σ A μ 1B σ A μ 2B σ A 4 -60.63 1
  8*) mixed: uni.-bi.-bi., modes differ μ A σ A μ 1B σ A μ 2B σ A μ 1C σ A μ 2C σ A 6 -56.86 6.58
  9*) mixed: uni.-bi.-uni. μ A σ A μ 1B σ B μ 2B σ B μ C σ C 7 -52.02 74
  1. The mean/mode parameter of the unimodal normal distribution is μ and the standard deviation is σ. The central tendency parameters for the modes in the bimodal normal distributions are μ1 and μ2 and the standard deviation for each mode is σ i . Within each model, parameters with the same subscript are constrained to be equal. Parameters for the best fit model (model 7, highlighted in bold) with 95% confidence intervals based on likelihood profile [51] in parentheses are μA = 0.28 (0.24–0.32), μ1B = 0.42 (0.38–0.46), μ2B = 0.10 (0.06–0.15), σA = 0.08 (0.07–0.11). Parameters for model 6 are μ1A = 0.21 (0.11–0.40), μ2A = 0.34 (0.11–0.40), μ1B = 0.42 (0.38–0.45), μ2B = 0.10 (0.06–0.14), σA = 0.07 (0.06–0.10). Model selection is based on Akaike's Information Criteria (AIC) which incorporates the number of estimated parameters (n). "Uni" = unimodal; "bi" = bimodal. The evidence ratio is the odds ratio of support for the best fit model over the listed model [50]; models with evidence ratios close to 1 are well-supported. Models that allow for a change in the distribution after sexual reproduction have an asterisk (*) after the model number.