Haines Grant E, Stuart Yoel E, Hanson Dieta, Tasneem Tania, Bolnick Daniel I, Larsson Hans C E, Hendry Andrew P
Redpath Museum and Department of Biology McGill University Montréal QC Canada.
Department of Biology Loyola University Chicago IL USA.
Ecol Evol. 2020 Nov 17;10(23):13297-13311. doi: 10.1002/ece3.6929. eCollection 2020 Dec.
Recent methodological advances have led to a rapid expansion of evolutionary studies employing three-dimensional landmark-based geometric morphometrics (GM). GM methods generally enable researchers to capture and compare complex shape phenotypes, and to quantify their relationship to environmental gradients. However, some recent studies have shown that the common, inexpensive, and relatively rapid two-dimensional GM methods can distort important information and produce misleading results because they cannot capture variation in the depth () dimension. We use micro-CT scanned threespine stickleback ( Linnaeus, 1758) from six parapatric lake-stream populations on Vancouver Island, British Columbia, to test whether the loss of the depth dimension in 2D GM studies results in misleading interpretations of parallel evolution. Using joint locations described with 2D or 3D landmarks, we compare results from separate 2D and 3D shape spaces, from a combined 2D-3D shape space, and from estimates of biomechanical function. We show that, although shape is distorted enough in 2D projections to strongly influence the interpretation of morphological parallelism, estimates of biomechanical function are relatively robust to the loss of the Z dimension.
近期方法学上的进展促使采用基于三维地标点的几何形态测量学（GM）的进化研究迅速扩展。GM方法通常使研究人员能够捕捉和比较复杂的形状表型，并量化它们与环境梯度的关系。然而，最近的一些研究表明，常见、廉价且相对快速的二维GM方法可能会扭曲重要信息并产生误导性结果，因为它们无法捕捉深度（）维度的变化。我们使用来自不列颠哥伦比亚省温哥华岛六个相邻湖泊 - 溪流种群的微计算机断层扫描（micro-CT）三刺鱼（Linnaeus，1758），来测试二维GM研究中深度维度的缺失是否会导致对平行进化的误导性解释。使用二维或三维地标点描述的关节位置，我们比较了来自单独的二维和三维形状空间、组合的二维 - 三维形状空间以及生物力学功能估计的结果。我们表明，尽管二维投影中的形状扭曲程度足以强烈影响形态平行性的解释，但生物力学功能估计对Z维度的缺失相对稳健。
