Abstract
We studied the time to speciation by geographic isolation for a species living on two islands connected by infrequent migration. Assumptions were that incompatibility was controlled by a finite number of quantitative loci, and individuals differing in loci of more than some threshold fraction do not mix genetically with each other. We also assumed sexual haploid species, each population being nearly monomorphic, and free recombination between loci for within-population processes. The genetic distance (defined as the fraction of loci differing between populations) followed stochastic processes, which were analyzed by means of stochastic differential equations, diffusion equations, and individual-based simulations. The distance increases by the accumulation of novel mutations but decreases by migration and hybridization. It may converge to a quasi-equilibrium around which it fluctuates thereafter. If the threshold fraction of speciation is controlled, the smallness of the number of incompatibility loci enhanced the magnitude of fluctuation around the quasi-equilibrium and shortened the time to speciation considerably. Novel species were created by mutation accumulation and repeated infrequent migration, and the rate of species creation was the fastest for an intermediate rate of migration. A smaller number of loci increased the optimal migration rate and the species creation rate.
| Original language | English |
|---|---|
| Pages (from-to) | 36-45 |
| Number of pages | 10 |
| Journal | Journal of Theoretical Biology |
| Volume | 405 |
| DOIs | |
| Publication status | Published - Sep 1 2016 |
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All Science Journal Classification (ASJC) codes
- Statistics and Probability
- Modelling and Simulation
- Biochemistry, Genetics and Molecular Biology(all)
- Immunology and Microbiology(all)
- Agricultural and Biological Sciences(all)
- Applied Mathematics
Cite this
Smallness of the number of incompatibility loci can facilitate parapatric speciation. / Yamaguchi, Ryo; Iwasa, Yoh.
In: Journal of Theoretical Biology, Vol. 405, 01.09.2016, p. 36-45.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Smallness of the number of incompatibility loci can facilitate parapatric speciation
AU - Yamaguchi, Ryo
AU - Iwasa, Yoh
PY - 2016/9/1
Y1 - 2016/9/1
N2 - We studied the time to speciation by geographic isolation for a species living on two islands connected by infrequent migration. Assumptions were that incompatibility was controlled by a finite number of quantitative loci, and individuals differing in loci of more than some threshold fraction do not mix genetically with each other. We also assumed sexual haploid species, each population being nearly monomorphic, and free recombination between loci for within-population processes. The genetic distance (defined as the fraction of loci differing between populations) followed stochastic processes, which were analyzed by means of stochastic differential equations, diffusion equations, and individual-based simulations. The distance increases by the accumulation of novel mutations but decreases by migration and hybridization. It may converge to a quasi-equilibrium around which it fluctuates thereafter. If the threshold fraction of speciation is controlled, the smallness of the number of incompatibility loci enhanced the magnitude of fluctuation around the quasi-equilibrium and shortened the time to speciation considerably. Novel species were created by mutation accumulation and repeated infrequent migration, and the rate of species creation was the fastest for an intermediate rate of migration. A smaller number of loci increased the optimal migration rate and the species creation rate.
AB - We studied the time to speciation by geographic isolation for a species living on two islands connected by infrequent migration. Assumptions were that incompatibility was controlled by a finite number of quantitative loci, and individuals differing in loci of more than some threshold fraction do not mix genetically with each other. We also assumed sexual haploid species, each population being nearly monomorphic, and free recombination between loci for within-population processes. The genetic distance (defined as the fraction of loci differing between populations) followed stochastic processes, which were analyzed by means of stochastic differential equations, diffusion equations, and individual-based simulations. The distance increases by the accumulation of novel mutations but decreases by migration and hybridization. It may converge to a quasi-equilibrium around which it fluctuates thereafter. If the threshold fraction of speciation is controlled, the smallness of the number of incompatibility loci enhanced the magnitude of fluctuation around the quasi-equilibrium and shortened the time to speciation considerably. Novel species were created by mutation accumulation and repeated infrequent migration, and the rate of species creation was the fastest for an intermediate rate of migration. A smaller number of loci increased the optimal migration rate and the species creation rate.
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U2 - 10.1016/j.jtbi.2015.10.024
DO - 10.1016/j.jtbi.2015.10.024
M3 - Article
C2 - 26582724
AN - SCOPUS:84947545223
VL - 405
SP - 36
EP - 45
JO - Journal of Theoretical Biology
JF - Journal of Theoretical Biology
SN - 0022-5193
ER -