Table 1. Comparison of genetic robustness in randomly (rand) and assortatively (asst) mating populations.

Genotype	AA			AB			BB			Total
Mating	rand	asst		rand	asst		rand	asst		rand	asst
Unfit phenotypes (%)	13.9	7.4	**	11.4	31.1	***	16.3	11.4	***	14.0	11.6	*
Increase (%) in unfit phenotypes	7.9	9.5	n.s.	8.2	0.0	***	16.5	17.6	n.s.	13.0	12.9	n.s.
N	187	913		962	206		1077	1127		2226	2246

Statistics are maximum likelihood χ2 values: n.s. = not significant,

*p<0.05,

**p<0.01,

***p<0.001.

Pairs of columns show the proportion of unfit phenotypes (those responding to one or more detrimental resources) for the labeled genotypes (AA, AB, and BB), as well as the population as a whole (Total). The first row of results pertains to the proportion of unfit phenotypes just before (rand) or soon after (asst) the invasion of the assortative mating gene (Methods). The second row of results pertains to the percentage increase in unfit phenotypes after the genotypes have been subject to single point mutations (Methods). Statistics indicate significant differences in the proportion of the functional phenotypes before and after the invasion of assortative mating, indicated for each row of results.