DIVERSITY‐DEPENDENT CLADOGENESIS AND TRAIT EVOLUTION IN THE ADAPTIVE RADIATION OF THE AUKS (AVES: ALCIDAE)
DIVERSITY‐DEPENDENT CLADOGENESIS AND TRAIT EVOLUTION IN THE ADAPTIVE RADIATION OF THE AUKS (AVES: ALCIDAE)
复制标题
海雀（鸟科：海雀科）适应性辐射中的多样性依赖的分支发生和性状进化
DOI：
10.1111/j.1558-5646.2012.01786.x
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发表时间：
2013
期刊：
影响因子：
3.3
通讯作者：
S. Mursleen
中科院分区：
文献类型：
--
作者：
J. Weir;S. Mursleen
通过适应性辐射的过程中，进化的进化速度的分支和生态相关的性状进化预计将放缓物种多样性的增加，生态位被占领，生态机会下降。我们开发了新的基于似然的模型来测试海雀的多样性依赖进化，海雀是适应水下“飞行”的少数几个海鸟家族之一，并且表现出各种各样的喙大小和形状。与适应性辐射的预期一致，我们发现随着多样性的增加，分支发生率（下降6倍）和喙形（下降64倍）进化率都有所下降。比尔形状分歧成两个分支在基础的分支事件，一个分支拥有大多长，窄的法案，主要用于饲料的鱼类，和其他短厚的法案，主要用于饲料的浮游生物。在这种最初的分歧，在法案的形状，大小，一个已知的相关猎物的大小和最大潜水深度，迅速分歧，在这些分支。这些结果表明，觅食性状的适应性辐射经历了最初的分化，在法案形状占据不同的食物资源，随后的大小分化，细分每个生态位沿着水柱的深度轴。
Through the course of an adaptive radiation, the evolutionary speed of cladogenesis and ecologically relevant trait evolution are expected to slow as species diversity increases, niches become occupied, and ecological opportunity declines. We develop new likelihood‐based models to test diversity‐dependent evolution in the auks, one of only a few families of seabirds adapted to underwater “flight,” and which exhibit a large variety of bill sizes and shapes. Consistent with the expectations of adaptive radiation, we find both a decline in rates of cladogenesis (a sixfold decline) and bill shape (a 64‐fold decline) evolution as diversity increased. Bill shape diverged into two clades at the basal cladogenesis event with one clade possessing mostly long, narrow bills used to forage primarily on fish, and the other with short thick bills used to forage primarily on plankton. Following this initial divergence in bill shape, size, a known correlate of both prey size and maximum diving depth, diverged rapidly within each of these clades. These results suggest that adaptive radiation in foraging traits underwent initial divergence in bill shape to occupy different food resources, followed by size differentiation to subdivide each niche along the depth axis of the water column.