Department of Anatomical Sciences, Midwestern University, Glendale, Arizona 85308.
Evolution. 2018 Dec;72(12):2781-2791. doi: 10.1111/evo.13637. Epub 2018 Nov 15.
There is abundant theoretical and empirical evidence for the influence of variational properties of populations on microevolution, and more limited support for their lasting impact during macroevolution. This study applies evolutionary quantitative genetic approaches to assess the long-term impact of within-population phenotypic variation and covariation (the P matrix) on population divergence in recent humans and species diversification in genus Homo. Similarity between the primary axes of within- and between-population craniofacial variation confirms a role for p in human population divergence, although diversification is not constrained to be unidimensional. The long term impact of the P matrix on craniofacial evolution is supported by higher-than-average evolvabilities along most branches of the Homo tree, but statistical uncertainty inherent in the data reduce confidence in this conclusion. Higher evolvability is not statistically correlated with increased rate of evolution, although the relationship is in the predicted direction. This is due in part to the high evolutionary rate on the early modern human branch despite its moderate level of evolvability. There was evidence for neutral evolution as well as directional and stabilizing selection during evolution of our genus during the Plio-Pleistocene using generalized genetic distance as a test statistic.
有大量理论和经验证据表明，种群的变异特性会对微观进化产生影响，但对其在宏观进化过程中持久影响的证据支持较为有限。本研究应用进化数量遗传学方法，评估了种群内表型变异和协变（P 矩阵）对近期人类种群分化和人属物种多样化的长期影响。种群内和种群间颅面变异的主成分之间的相似性证实了 P 矩阵在人类种群分化中的作用，尽管多样化并不局限于单维。P 矩阵对颅面进化的长期影响得到了支持，因为在人属树的大多数分支上，大多数性状的可进化性都高于平均水平，但数据中固有的统计不确定性降低了对这一结论的信心。尽管方向一致，但可进化性与进化率的增加没有统计学上的相关性。这部分是由于早期现代人分支的进化率很高，尽管其可进化性中等。在更新世期间，使用广义遗传距离作为检验统计量，我们发现人属的进化过程中存在中性进化以及定向和稳定选择的证据。
