Anatomical diversification of a skeletal novelty in bat feet
Anatomical diversification of a skeletal novelty in bat feet
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DOI：
10.1111/evo.13786
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发表时间：
2018-12
期刊：
影响因子：
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通讯作者：
Kathryn E. Stanchak;J. Arbour;S. Santana
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文献类型：
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作者：
Kathryn E. Stanchak;J. Arbour;S. Santana
在不同的脊椎动物谱系中发现了新形态的、膜相关的骨骼棒，但对它们的进化知之甚少。在这里，我们展示了这些元素之一-蝙蝠的甲骨(翼手目)-是一种骨骼新奇的东西，在解剖学上具有多样性。我们对足距进化模型的比较和相应的时间差异分析表明，在翼手目进化史的早期，由于蝙蝠在进化飞行能力后进行了系统的辐射，所以足距是多样化的。我们发现各种解剖参数的种间差异对Calcar的功能可能很重要，这表明Calcar提供的适应优势导致了它的解剖多样性。除了整个长度，我们发现不同蝙蝠的跟骨在其组织成分上是不同的，在某些物种的跟骨和跟骨之间的关节处存在滑膜关节。这表明Calcar具有运动学功能作用。我们的结果表明，新的骨骼增加可以整合到脊椎动物的身体计划中，随后演变成各种形式，通过扩大生物体可以进化到的可用形态空间，潜在地影响分支多样性。
Neomorphic, membrane-associated skeletal rods are found in disparate vertebrate lineages, but their evolution is poorly understood. Here we show that one of these elements—the calcar of bats (Chiroptera)—is a skeletal novelty that has anatomically diversified. Our comparisons of evolutionary models of calcar length and corresponding disparity-through-time analyses indicate that the calcar diversified early in the evolutionary history of Chiroptera, as bats systematically radiated after evolving the capacity for flight. We find interspecific variation in a variety of anatomical parameters of probable importance for calcar function, which suggests that adaptive advantages provided by the calcar led to its anatomical diversification. In addition to overall length, we find that the calcar varies among bats in its tissue composition, and a synovial joint is present at the articulation between the calcar and the calcaneus ankle bone in some species. This suggests the calcar has a kinematic functional role. Our results demonstrate that novel skeletal additions can become integrated into vertebrate body plans and subsequently evolve into a variety of forms, potentially impacting clade diversification by expanding the available morphological space into which organisms can evolve.