Abstract：
Diverse clades of fishes adapted to feeding on the benthos repeatedly converge on steep craniofacial profiles and shorter, wider heads. But in an incipient radiation, to what extent is this morphological evolution measurable and can we distinguish the relative genetic vs. plastic effects? We use the Trinidadian guppy (Poecilia reticulata) to test the repeatability of adaptation and the alignment of genetic and environmental effects shaping poecilid craniofacial morphology. We compare wild-caught and common garden lab-reared fish to quantify the genetic and plastic components of craniofacial morphology across 4 populations from 2 river drainage systems (n = 56 total). We first use micro-computed tomography to capture 3D morphology, then place both landmarks and semilandmarks to perform size-corrected 3D morphometrics and quantify shape space. We find a measurable, significant, and repeatable divergence in craniofacial shape between high-predation invertivore and low-predation detritivore populations. As predicted from previous examples of piscine adaptive trophic divergence, we find increases in head slope and craniofacial compression among the benthic detritivore foragers. Furthermore, the effects of environmental plasticity among benthic detritivores produce exaggerated craniofacial morphological change along a parallel axis to genetic morphological adaptation from invertivore ancestors. Overall, many of the major patterns of benthic-limnetic craniofacial evolution appear convergent among disparate groups of teleost fishes.
摘要：
适应以底栖动物为食的多种鱼类在陡峭的颅面轮廓和较短的轮廓上反复会聚，更宽的头。但是在初期辐射中，这种形态进化在多大程度上是可测量的，我们能区分相对遗传与塑料效果？我们使用特立尼达孔雀鱼（Poeciliareticulata）来测试适应性的可重复性以及遗传和环境效应对形成poecilid颅面形态的一致性。我们比较了野生捕获和普通花园实验室饲养的鱼类，以量化来自两个河流排水系统（总共n=56）的四个种群的颅面形态的遗传和塑料成分。我们首先使用microCT来捕获3D形态学，然后放置地标和半地标以执行尺寸校正的3D形态计量学并量化形状空间。我们发现一个可衡量的，重要的,以及高捕食倒置和低捕食有害种群之间颅面形状的可重复差异。正如从先前的鱼类适应性营养差异实例预测的那样，我们发现底栖有害觅食者的头部斜率和颅面压缩增加。此外，底栖动物中环境可塑性的影响会沿平行轴产生夸张的颅面形态变化，以适应反向祖先的遗传形态。总的来说,底栖-边缘颅面演化的许多主要模式似乎在不同的硬骨鱼群中趋同。
