Pélabon C, Hansen T F, Carter A J R, Houle D
Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway.
J Evol Biol. 2006 May;19(3):764-76. doi: 10.1111/j.1420-9101.2005.01054.x.
We tested whether directional selection on an index-based wing character in Drosophila melanogaster affected developmental stability and patterns of directional asymmetry. We selected for both an increase (up selection) and a decrease (down selection) of the index value on the left wing and compared patterns of fluctuating and directional asymmetry in the selection index and other wing traits across selection lines. Changes in fluctuating asymmetry across selection lines were predominantly small, but we observed a tendency for fluctuating asymmetry to decrease in the up-selected lines in both replicates. Because changes in fluctuating asymmetry depended on the direction of selection, and were not related to changes in trait size, these results fail to support existing hypotheses linking directional selection and developmental stability. Selection also produced a pattern of directional asymmetry that was similar in all selected lines whatever the direction of selection. This result may be interpreted as a release of genetic variance in directional asymmetry under selection.
我们测试了对黑腹果蝇基于指数的翅性状进行定向选择是否会影响发育稳定性和定向不对称模式。我们对左翼指数值进行了增加（向上选择）和减少（向下选择）的选择，并比较了各选择系中选择指数和其他翅性状的波动不对称和定向不对称模式。各选择系中波动不对称的变化大多较小，但在两个重复实验中，我们都观察到向上选择系中波动不对称有减小的趋势。由于波动不对称的变化取决于选择方向，且与性状大小的变化无关，这些结果未能支持将定向选择与发育稳定性联系起来的现有假说。选择还产生了一种定向不对称模式，无论选择方向如何，所有选择系中的这种模式都相似。这一结果可解释为选择作用下定向不对称中遗传方差的释放。
