LTER: Polymorphism and Differentiation in Poecilia latipinna

一个物种的本地种群通常被认为是遗传分化的，这是对产生不同自然选择力量的环境因素的本地差异的反应。这种“适应性分化”的大多数论证实际上不是基于当地种群，而是集中在地理距离很远或完全没有基因流动联系的种群上。因此，适应性分化可能发生的规模仍有待划定。特拉维斯博士先前的研究表明，对不同部位的物理因素的明显反应存在广泛的局部差异。研究的下一阶段将(1)检查遗传差异的详细性质，(2)测试环境中的物理因素如何产生自然选择的不同力量的假设。

Local populations of a species are often considered to be genetically differentiated in response to local differences in environmental factors that produce divergent forces of natural selection. Most demonstrations of such "adaptive differentiation" are actually not based on local populations but are instead focused on populations that are separated by large geographic distances or are completely unconnected by gene flow. Thus the scale at which adaptive differentiation can occur remains to be delineated. Prior work by Dr. Travis has shown extensive local differentiation in apparent response to physical factors that vary across locations. The next phase of the research will (1) examine the detailed nature of the genetic differences and (2) test the hypotheses for how the physical factors in the environment generate divergent forces of natural selection.