The rates of self-fertilization (s), disassortative mating among morphs (d), and year-to-year survival (I) were set to values likely for populations of species like L.
Weakening of self-incompatibility could result in increased self-fertilization and reduced disassortative mating among morphs.
Varying individual parameters, such as the rate of year-to-year survival (I) or the levels of self-fertilization (s) and disassortative mating (d), delayed equilibrium for a maximum of 75 yr for extreme values of I and 200 yr for extreme values of s [ILLUSTRATION FOR FIGURE 6A, B, C OMITTED].
verticillatus, the combination of reproductive and life history parameters and weak disassortative mating (Eckert 1993, Eckert and Barrett 1993b, 1994b) may preserve historically skewed morph ratios for very long periods of time.
The morph ratio in populations of tristylous species is governed by an interaction between frequency-dependent selection due to disassortative mating and stochastic processes.
If there are no inherent fitness-differences among morphs, then disassortative mating during the reproductive cycle is expected to result in more even morph frequencies in the progeny than in the parental generation (Fisher and Mather 1943).
In one set of simulations, they examined the influence of survival on time to equilibrium in an outcrossing tristylous species with almost complete disassortative mating (i.
For each disassortative mating event, the paternal parent was selected randomly from all parents that were a different morph than the maternal parent.
For populations in which the morphs occurred at equal frequency, disassortative mating had no effect on [N.
lms] = N because of the absence of disassortative mating.
In contrast, populations with fewer than 40 individuals were most likely to lose morphs, despite strong levels of disassortative mating.
While the values for mating parameters were set similarly for all population size treatments, actual levels of disassortative mating monitored during the simulations were correlated with population size.