Phylogenetic, functional, and structural components of variation in bone growth rate of amniotes
Phylogenetic, functional, and structural components of variation in bone growth rate of amniotes
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DOI：
10.1111/j.1525-142x.2008.00229.x
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发表时间：
2008-03-01
影响因子：
2.9
通讯作者：
Desdevises, Yves
中科院分区：
文献类型：
--
作者：
Cubo, Jorge;Legendre, Pierre;Desdevises, Yves
在每一个生物体中观察到的生物学特征是三组因素的结果：历史（通过同源遗传），功能（生物适应）和结构（构成器官的材料固有的特性，以及它们生长的形态发生规则）。将它们整合起来，就能对经验数据给出令人满意的因果解释。然而，在实现这一目标的实践中几乎没有取得进展，因为缺乏一种方法上有效的工具。在这里，我们使用一种新的变异划分的统计方法来分析羊膜骨生长。(1)历史成分。骨生长速率的变化包含一个重要的系统发育信号，表明观察到的模式部分是共同祖先的结果。(2)功能因果关系。高生长率虽然消耗能量，但对于生长期较短的分类群（如鸟类）可能是适应性的（即，它们可能提高存活率）。在恒温羊膜动物中，低静息代谢率可能限制最大可能的生长速率。(3)结构约束。软组织的生长是一个乘法过程，而矿化组织的生长是增生的（加性的，即矿化锋面只发生在自由表面）。许多羊膜的骨生长部分地绕过了这一限制：它不仅在骨轴的外表面实现，而且在骨皮质的空腔内也实现，因为它是离心生长的。我们的方法有助于历史主义、功能主义和结构主义的统一，以实现更完整的进化生物学。
The biological features observed in every living organism are the outcome of three sets of factors: historical (inherited by homology), functional (biological adaptation), and structural (properties inherent to the materials with which organs are constructed, and the morphogenetic rules by which they grow). Integrating them should bring satisfactory causal explanations of empirical data. However, little progress has been accomplished in practice toward this goal, because a methodologically efficient tool was lacking. Here we use a new statistical method of variation partitioning to analyze bone growth in amniotes. (1) Historical component. The variation of bone growth rates contains a significant phylogenetic signal, suggesting that the observed patterns are partly the outcome of shared ancestry. (2) Functional causation. High growth rates, although energy costly, may be adaptive (i.e., they may increase survival rates) in taxa showing short growth periods (e.g., birds). In ectothermic amniotes, low resting metabolic rates may limit the maximum possible growth rates. (3) Structural constraint. Whereas soft tissues grow through a multiplicative process, growth of mineralized tissues is accretionary (additive, i.e., mineralization fronts occur only at free surfaces). Bone growth of many amniotes partially circumvents this constraint: it is achieved not only at the external surface of the bone shaft, but also within cavities included in the bone cortex as it grows centrifugally. Our approach contributes to the unification of historicism, functionalism, and structuralism toward a more integrated evolutionary biology.