♦ Programs

Local adaptation and/or reinforcement

        This program is essentially the one used in (please refer to this paper for a full description):

        Servedio, M.R.  2004.  The evolution of premating isolation: local adaptation and natural and sexual selection against hybrids. Evolution 58:913-924.

        In short, this program explores the situation of secondary contact on two islands in a 4 locus reinforcement model.  There is a locally adapted trait (T locus) with specific alleles (T1 and T2) that cause high fitness (sT) on one of each of two islands (1 and 2 respectively).  Selection against hybrids is caused by mismatches at the species identity loci N and M (e.g., N1M2 and N2M1 have low fitness - selection favors the purebreds N1M1 and N2M2 with coefficient sE).  The population is initially fixed for allele A1, which codes for random mating at the A locus.  The simulation analyses the spread of the allele A2, which causes nonrandom mating.  More specifically, females with allele A2 will prefer males that share their T allele with strength c2 (alpha2 in Servedio 2004), and will prefer males that share their NM genotype with strength d2 (beta2 in Servedio 2004). 

        When sT and c2 are non-zero, the spread of assortative mating is occurring because of local adaptation of the mating cue (T).

        When sT, sE, and c2 are non-zero, assortative mating is evolving by "indicator" reinforcement (the mating cue, T, is an indicator of the probable genotype at the species identity loci).

        When sE and d2 are non-zero, assortative mating is evolving because of prefernces for the proper purebreds.  This may occur through a combination of species recognition and pleiotropic effects of species identity loci on appearance and fitness (see Servedio 2004 for development of this idea).

        When sE, sT, c2 and d2 are all non-zero, assortative mating is based on the total phenotype (at the trait T and species identity NM loci).

        Similar programs have been used in other reinforcement papers by Servedio, which may describe other effects that the user can find by exploring the parameter space.

        The user may assign the parameter values for sT, sE, c2, d2, the migration rate, recombination rates between loci, and other values using the "reinfparams" file.  This file must be downloaded along with the main application. 

         Code (in C) for the program can be obtained by e-mailing Servedio at servedio@email.unc.edu. This work was funded by NSF grant DEB 0234849. (Any opinions, findings, and conclusions or recommendations expressed in this material are   those of the author and do not necessarily reflect the view of the National Science Foundation.)

                     download parameter file-Mac                        download application-Mac

                     download parameter file-PC                          download application-PC

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