Speciation and the "shifting balance" in a continuous population

article Speciation and the "shifting balance" in a continuous population published yes Shahin Rouhani author Nicholas H Barton author 4880FE40-F248-11E8-B48F-1D18A9856A870000-0002-8548-5240 Shifts between adaptive peaks, caused by sampling drift, are involved in both speciation and adaptation via Wright's “shiftingbalance.” We use techniques from statistical mechanics to calculate the rate of such transitions for apopulation in a single panmictic deme and for apopulation which is continuously distributed over one- and two-dimensional regions. This calculation applies in the limit where transitions are rare. Our results indicate that stochastic divergence is feasible despite free gene flow, provided that neighbourhood size is low enough. In two dimensions, the rate of transition depends primarily on neighbourhood size N and only weakly on selection pressure (≈sk exp(− cN)), where k is a number determined by the local population structure, in contrast with the exponential dependence on selection pressure in one dimension (≈exp(− cN √s)) or in a single deme (≈exp(− cNs)). Our calculations agree with simulations of a single deme and a one-dimensional population. Elsevier1987 eng Theoretical Population Biology 0040-5809 1096-032510.1016/0040-5809(87)90016-5 313465 - 492 yes S. Rouhani and N. H. Barton, “Speciation and the &quot;shifting balance&quot; in a continuous population,” Theoretical Population Biology, vol. 31, no. 3. Elsevier, pp. 465–492, 1987. Rouhani, S., & Barton, N. H. (1987). Speciation and the &quot;shifting balance&quot; in a continuous population. Theoretical Population Biology. Elsevier. <a href="https://doi.org/10.1016/0040-5809(87)90016-5">https://doi.org/10.1016/0040-5809(87)90016-5</a> Rouhani, Shahin, and Nicholas H Barton. “Speciation and the &quot;Shifting Balance&quot; in a Continuous Population.” Theoretical Population Biology. Elsevier, 1987. <a href="https://doi.org/10.1016/0040-5809(87)90016-5">https://doi.org/10.1016/0040-5809(87)90016-5</a>. S. Rouhani, N.H. Barton, Theoretical Population Biology 31 (1987) 465–492. Rouhani S, Barton NH. 1987. Speciation and the &quot;shifting balance&quot; in a continuous population. Theoretical Population Biology. 31(3), 465–492. Rouhani, Shahin, and Nicholas H. Barton. “Speciation and the &quot;Shifting Balance&quot; in a Continuous Population.” Theoretical Population Biology, vol. 31, no. 3, Elsevier, 1987, pp. 465–92, doi:<a href="https://doi.org/10.1016/0040-5809(87)90016-5">10.1016/0040-5809(87)90016-5</a>. Rouhani S, Barton NH. Speciation and the &quot;shifting balance&quot; in a continuous population. Theoretical Population Biology. 1987;31(3):465-492. doi:<a href="https://doi.org/10.1016/0040-5809(87)90016-5">10.1016/0040-5809(87)90016-5</a> 36572018-12-11T12:04:28Z2022-02-04T12:30:10Z