Department of Ecology, Evolution and Behavior, University of Minnesota, 1479 Gortner Ave 140 Gortner Lab, St Paul, MN, 55108, USA.
Mol Ecol. 2016 Dec;25(24):6009-6011. doi: 10.1111/mec.13926.
Phenotypic plasticity has been hypothesized to play a central role in the evolution of phenotypic diversity across species (West-Eberhard ). Through 'genetic assimilation', phenotypes that are initially environmentally induced within species become genetically fixed over evolutionary time. While genetic assimilation has been shown to occur in both the laboratory and the field (Waddington ; Aubret & Shine ), it remains to be shown whether it can account for broad patterns of phenotypic diversity across entire adaptive radiations. Furthermore, our ignorance of the underlying molecular mechanisms has hampered our ability to incorporate phenotypic plasticity into models of evolutionary processes. In this issue of Molecular Ecology, Parsons et al. () take a significant step in filling these conceptual gaps making use of cichlid fishes as a powerful study system. Cichlid jaw and skull morphology show adaptive, plastic changes in response to early dietary experiences (Fig. 1). In this research, Parsons et al. () first show that the direction of phenotypic plasticity aligns with the major axis of phenotypic divergence across species. They then dissect the underlying genetic architecture of this plasticity, showing that it is specific to the developmental environment and implicating the patched locus in genetic assimilation (i.e. a reduction in the environmental sensitivity of that locus in the derived species).
表型可塑性被假设在物种间表型多样性的进化中起着核心作用 (West-Eberhard)。通过“遗传同化”，最初在物种内由环境引起的表型在进化过程中逐渐固定下来。虽然遗传同化已被证明在实验室和野外都存在 (Waddington; Aubret & Shine)，但它是否能够解释整个适应辐射中广泛的表型多样性模式仍有待证明。此外，我们对潜在分子机制的无知阻碍了我们将表型可塑性纳入进化过程模型的能力。在本期《分子生态学》中，Parsons 等人 () 利用慈鲷鱼作为强大的研究系统，在填补这些概念空白方面迈出了重要的一步。慈鲷鱼的颚和颅骨形态会对早期的饮食经验做出适应性、可塑的变化 (图 1)。在这项研究中，Parsons 等人 () 首先表明表型可塑性的方向与物种间表型分歧的主轴一致。然后，他们剖析了这种可塑性的潜在遗传结构，表明它是特定于发育环境的，并暗示了 patched 基因座在遗传同化中的作用（即该基因座在衍生物种中对环境敏感性的降低）。
