Hansen Thomas F, Martins Emília P
University of Oslo, Division of Zoology, Department of Biology, P. O. Box 1050, Blindern, N 0316, Oslo 3, Norway.
Department of Biology, University of Oregon, Eugene, Oregon, 97403.
Evolution. 1996 Aug;50(4):1404-1417. doi: 10.1111/j.1558-5646.1996.tb03914.x.
As species evolve along a phylogenetic tree, we expect closely related species to retain some phenotypic similarities due to their shared evolutionary histories. The amount of expected similarity depends both on the hierarchical phylogenetic structure, and on the specific magnitude and types of evolutionary changes that accumulate during each generation. In this study, we show how models of microevolutionary change can be translated into the resulting macroevolutionary patterns. We illustrate how the structure of phenotypic covariances expected in interspecific measurements can be derived, and how this structure depends on the microevolutionary forces guiding phenotypic change at each generation. We then explore the covariance structure expected from several simple microevolutionary models of phenotypic evolution, including various combinations of random genetic drift, directional selection, stabilizing selection, and environmental change, as well as models of punctuated or burst-like evolution. We find that stabilizing selection leads to patterns of exponential decrease of between species covariance with phylogenetic distance. This is different from the usual linear patterns of decrease assumed in most comparative and systematic methods. Nevertheless, linear patterns of decrease can result from many processes in addition to random genetic drift, such as directional and fluctuating selection as well as modes of punctuated change. Our framework can be used to develop methods for (1) phylogenetic reconstruction; (2) inference of the evolutionary process from comparative data; and (3) conducting or evaluating statistical analyses of comparative data while taking phylogenetic history into account.
随着物种沿着系统发育树进化，我们预期亲缘关系较近的物种由于共享的进化历史而保留一些表型相似性。预期的相似程度既取决于系统发育的层次结构，也取决于每一代积累的进化变化的具体幅度和类型。在本研究中，我们展示了微观进化变化模型如何转化为由此产生的宏观进化模式。我们说明了如何推导种间测量中预期的表型协方差结构，以及这种结构如何取决于指导每一代表型变化的微观进化力量。然后，我们探讨了从几个简单的表型进化微观进化模型预期的协方差结构，包括随机遗传漂变、定向选择、稳定选择和环境变化的各种组合，以及间断或爆发式进化模型。我们发现稳定选择导致种间协方差随系统发育距离呈指数下降模式。这与大多数比较和系统发育方法中通常假设的线性下降模式不同。然而，除了随机遗传漂变之外，许多过程也可能导致线性下降模式，如定向和波动选择以及间断变化模式。我们的框架可用于开发以下方法：（1）系统发育重建；（2）从比较数据推断进化过程；（3）在考虑系统发育历史的同时进行或评估比较数据的统计分析。
