Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06369, USA.
Science. 2018 Feb 16;359(6377):765-770. doi: 10.1126/science.aap9125.
Predicting evolution remains difficult. We studied the evolution of cryptic body coloration and pattern in a stick insect using 25 years of field data, experiments, and genomics. We found that evolution is more difficult to predict when it involves a balance between multiple selective factors and uncertainty in environmental conditions than when it involves feedback loops that cause consistent back-and-forth fluctuations. Specifically, changes in color-morph frequencies are modestly predictable through time ( = 0.14) and driven by complex selective regimes and yearly fluctuations in climate. In contrast, temporal changes in pattern-morph frequencies are highly predictable due to negative frequency-dependent selection ( = 0.86). For both traits, however, natural selection drives evolution around a dynamic equilibrium, providing some predictability to the process.
预测进化仍然具有挑战性。我们使用 25 年的野外数据、实验和基因组学研究了一种竹节虫隐性体色和图案的进化。我们发现，当进化涉及到多种选择因素之间的平衡以及环境条件的不确定性时，比涉及到导致一致的往返波动的反馈循环时，进化更难预测。具体来说，颜色形态频率的变化在时间上（ = 0.14）是可以适度预测的，这是由复杂的选择机制和气候的年际波动驱动的。相比之下，由于负频率依赖性选择（ = 0.86），图案形态频率的时间变化具有高度可预测性。然而，对于这两个特征，自然选择都使进化围绕动态平衡进行，从而为这一过程提供了一定的可预测性。
