Björklund M
Department of Zoology, Uppsala University, Sweden.
J Theor Biol. 1994 Dec 21;171(4):427-30. doi: 10.1006/jtbi.1994.1246.
Selection processes of entities higher than individuals have recently been suggested to play a potential role in macroevolution. In particular, population level traits such as variability seem likely candidates for higher-level selection processes because they interact with population fitness (survival). In this paper, I expand on that theme and argue that a population level trait, such as organismal integration, measured by the genetic variance-covariance matrix, can be subject to interpopulational selection. This is so because a population consisting of individuals with a high degree of integration will respond faster to selection than a less integrated one, and thus more rapidly reach new optima. This idea generates a number of predictions which are supported by data from natural and laboratory populations of a diverse array of organisms. First, the level of genetic integration in morphological characters is generally quite high. Second, there are a number of cases where the within- and among-population correlation matrices are similarly oriented. Third, the main pattern of morphological variation in birds is that species within genera are most exclusively oriented along a size-axis. These results are consistent with the ideas put forward in this paper, though not providing conclusive evidence.
最近有人提出，高于个体层面的实体选择过程可能在宏观进化中发挥作用。特别是，诸如变异性等种群水平的特征似乎很可能是更高层次选择过程的候选因素，因为它们与种群适应性（生存）相互作用。在本文中，我将扩展这一主题，并认为通过遗传方差协方差矩阵测量的种群水平特征，如生物体整合，可能会受到种群间选择的影响。之所以如此，是因为由高度整合的个体组成的种群对选择的反应会比整合程度较低的种群更快，从而能更快地达到新的最优状态。这一观点产生了许多预测，来自各种生物的自然种群和实验室种群的数据支持了这些预测。第一，形态特征的遗传整合水平通常相当高。第二，在许多情况下，种群内和种群间的相关矩阵方向相似。第三，鸟类形态变异的主要模式是，属内物种最主要沿着大小轴分布。这些结果与本文提出的观点一致，尽管没有提供确凿的证据。
