Department of Botany and Plant Sciences and Program in Genetics, University of California, Riverside, CA 92521-0124.
Proc Natl Acad Sci U S A. 1989 Nov;86(22):9044-7. doi: 10.1073/pnas.86.22.9044.
Gene flow can have an especially strong impact on the evolution of small populations. However, empirical studies on the actual rates and patterns of gene flow into small populations are few. Thus, we sought to measure gene flow into small populations of wild radish. Raphanus sativus. We found significant differences in gene flow receipt among experimental populations and within those populations over a season. A maximum-likelihood estimate revealed that almost all of the gene flow into these synthetic populations had its origin in relatively distant (>650 m), large natural populations rather than the proximal (255-400 m), small synthetic populations. We also estimated rates of interpopulation mating from simple paternity analysis of progeny produced by seven small (ca. 50 plants) natural populations. Again, we found significant heterogeneity in gene flow receipt. Although these populations varied 10-fold in their range of isolation distances (100-1000 m), gene flow rates did not vary with distance. The magnitude of gene flow rates estimated in all but one population was great enough for gene flow to play an important role in the evolution of these small populations.
基因流对小种群的进化可能有特别强烈的影响。然而，关于基因流入小种群的实际速率和模式的实证研究却很少。因此，我们试图测量野萝卜（Raphanus sativus）小种群的基因流入情况。我们发现，在一个季节内，实验种群和种群内的基因流入接收存在显著差异。最大似然估计显示，这些合成种群中几乎所有的基因流入都源自相对较远（>650 米）、大的自然种群，而不是近端（255-400 米）、小的合成种群。我们还通过对来自七个小（约 50 株）自然种群的后代进行简单的亲子分析，估计了种群间交配的比率。同样，我们发现基因流入接收存在显著的异质性。尽管这些种群的隔离距离范围（100-1000 米）相差 10 倍，但基因流动率并不随距离而变化。除了一个种群之外，所有种群的基因流动率估计值都很大，足以使基因流动在这些小种群的进化中发挥重要作用。
