article published yes Nicholas H Barton author 4880FE40-F248-11E8-B48F-1D18A9856A870000-0002-8548-5240 The effect of a cline as a barrier to gene flow at closely linked, weakly selected loci is investigated using a continuous diffusion model. It is shown that a linked cline induces a step in the frequency of a neutral allele, which is proportional to the gradient in neutral allele frequency and to the inverse of the recombination rate. A barrier to dispersal or a local region of low abundance has a similar effect (Nagylaki, 1976). The cline will block the flow of neutral alleles over a region of chromosome roughly 2s/t map units long. However, a slightly advantageous allele will be little affected, and must be very tightly linked to be delayed for long. Springer Nature1979 eng 0018-067X 1365-254010.1038/hdy.1979.86 433333 - 339 yes Barton NH. 1979. Gene flow past a cline. Heredity. 43(3), 333–339. Barton, Nicholas H. “Gene Flow Past a Cline.” <i>Heredity</i>, vol. 43, no. 3, Springer Nature, 1979, pp. 333–39, doi:<a href="https://doi.org/10.1038/hdy.1979.86">10.1038/hdy.1979.86</a>. Barton, Nicholas H. “Gene Flow Past a Cline.” <i>Heredity</i>. Springer Nature, 1979. <a href="https://doi.org/10.1038/hdy.1979.86">https://doi.org/10.1038/hdy.1979.86</a>. N.H. Barton, Heredity 43 (1979) 333–339. Barton, N. H. (1979). Gene flow past a cline. <i>Heredity</i>. Springer Nature. <a href="https://doi.org/10.1038/hdy.1979.86">https://doi.org/10.1038/hdy.1979.86</a> N. H. Barton, “Gene flow past a cline,” <i>Heredity</i>, vol. 43, no. 3. Springer Nature, pp. 333–339, 1979. Barton NH. Gene flow past a cline. <i>Heredity</i>. 1979;43(3):333-339. doi:<a href="https://doi.org/10.1038/hdy.1979.86">10.1038/hdy.1979.86</a> 36732018-12-11T12:04:33Z2021-12-15T15:16:50Z