Gredler Jennifer N, Hish Alexander J, Noor Mohamed A F
From the Biology Department, Duke University, Durham, NC 27708.
J Hered. 2015 Jul-Aug;106(4):407-11. doi: 10.1093/jhered/esv027. Epub 2015 May 11.
Many molecular ecological and evolutionary studies sample wild populations at a single point in time, but that data represents genetic variation from a potentially unrepresentative snapshot in time. Variation across time in genetic parameters may occur quickly in species that produce multiple generations of offspring per year. Here, we compare genetic diversity in wild caught populations of Drosophila persimilis and Drosophila pseudoobscura collected 16 years apart at the same time of year and same site at 4 X-linked and 2 mitochondrial loci to assess genetic stability. We found no major changes in nucleotide diversity in either species, but we observed a drastic shift in Tajima's D between D. pseudoobscura timepoints at 1 locus associated with increased abundance of a set of related haplotypes. Our data also suggests that D. persimilis may have recently accelerated its demographic expansion. While the changes we observed were modest, this study reinforces the importance of considering potential temporal variation in genetic parameters within single populations over short evolutionary timescales.
许多分子生态学和进化研究在单个时间点对野生种群进行采样，但这些数据代表的是来自一个可能不具代表性的时间快照的遗传变异。在每年产生多代后代的物种中，遗传参数随时间的变化可能很快。在这里，我们比较了在一年中的同一时间和同一地点，相隔16年采集的野生黑腹果蝇和拟暗果蝇种群在4个X连锁基因座和2个线粒体基因座上的遗传多样性，以评估遗传稳定性。我们发现这两个物种的核苷酸多样性都没有重大变化，但我们观察到拟暗果蝇两个时间点之间在1个基因座上的 Tajima's D 发生了剧烈变化，这与一组相关单倍型丰度的增加有关。我们的数据还表明，黑腹果蝇可能最近加速了其种群扩张。虽然我们观察到的变化不大，但这项研究强化了在短进化时间尺度内考虑单个种群遗传参数潜在时间变化的重要性。
