Sackler Educational Laboratory for Comparative Genomics and Human Origins, American Museum of Natural History, New York, NY 10024;
Department of Anatomy, Midwestern University, Glendale, AZ 85308.
Proc Natl Acad Sci U S A. 2018 Nov 6;115(45):11501-11506. doi: 10.1073/pnas.1802651115. Epub 2018 Oct 22.
Natural selection, developmental constraint, and plasticity have all been invoked as explanations for intraspecific cranial variation in humans and apes. However, global patterns of human cranial variation are congruent with patterns of genetic variation, demonstrating that population history has influenced cranial variation in humans. Here we show that this finding is not unique to but is also broadly evident across extant ape species. Specifically, taxa that exhibit greater intraspecific cranial shape variation also exhibit greater genetic diversity at neutral autosomal loci. Thus, cranial shape variation within hominoid taxa reflects the population history of each species. Our results suggest that neutral evolutionary processes such as mutation, gene flow, and genetic drift have played an important role in generating cranial variation within species. These findings are consistent with previous work on human cranial morphology and improve our understanding of the evolutionary processes that generate intraspecific cranial shape diversity within hominoids. This work has implications for the analysis of selective and developmental pressures on the cranium and for interpreting shape variation in fossil hominin crania.
自然选择、发育约束和可塑性都被用来解释人类和猿类的种内颅骨变异。然而，人类颅骨变异的全球模式与遗传变异模式一致，表明种群历史影响了人类的颅骨变异。在这里，我们表明，这一发现不仅在中存在，而且在现生的猿类物种中也广泛存在。具体来说，表现出更大的种内颅骨形状变异的分类单元在中性常染色体基因座上也表现出更大的遗传多样性。因此，人科分类单元内的颅骨形状变异反映了每个物种的种群历史。我们的研究结果表明，中性进化过程（如突变、基因流和遗传漂变）在物种内产生颅骨变异方面发挥了重要作用。这些发现与之前关于人类颅骨形态的研究一致，并提高了我们对产生人科种内颅骨形状多样性的进化过程的理解。这项工作对分析颅骨上的选择和发育压力以及解释化石人科颅骨的形状变异具有重要意义。
