Breathing air in air: In what ways might extant amphibious fish biology relate to prevailing concepts about early tetrapods, the evolution of vertebrate air breathing, and the vertebrate land transition?
Breathing air in air: In what ways might extant amphibious fish biology relate to prevailing concepts about early tetrapods, the evolution of vertebrate air breathing, and the vertebrate land transition?
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DOI：
10.1086/425184
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发表时间：
2004-09-01
影响因子：
1.6
通讯作者：
Lee, HJ
中科院分区：
文献类型：
--
作者：
Graham, JB;Lee, HJ
呼吸空气的鱼类作为古生代脊椎动物呼吸空气的进化和向陆地过渡的可能模式具有启发性的重要意义。最近的一个假说，这种转变表明，海洋两栖鱼类的多样性组合主要发生在热带，高潮间带栖息地的早期四足动物的类似物，潮间带，而不是热带淡水低地，是跳板栖息地的泥盆纪陆地过渡的脊椎动物。在这里，我们认为，在潮间带的生活所施加的选择压力是不够的，导致所需的空气呼吸能力或程度的脊椎动物的土地过渡所需的水分离。现存的海洋两栖鱼类主要出现在岩石海岸或泥滩上，已经达到了它们向陆地生态位扩张的极限，并且通过呼吸结构与水保持联系，这些呼吸结构在空气中效率较低，比肺更容易干燥。我们进一步认为，进化的偶然性驱动的泥盆纪起源的四足动物标志着一个临界点的生活方式的分歧，选择压力将操作的生理，形态和自然历史的不同的脊椎动物群体。虽然在一些原始的硬骨鱼和一些两栖动物的栖息地长期缺氧和浅水条件出现类似的条件下，普遍存在于泥盆纪，显着不同的选择压力已运作在其他两栖动物和硬骨鱼超过3亿年以来的脊椎动物的土地过渡。例如，现存两栖动物的卵发育和幼虫变态主要是为了补偿栖息地水质的不确定性，甚至是通过最小化发育所需的时间来补偿缺水。相反，大多数潮间带（和两栖）鱼类的繁殖，所有这些都是硬骨鱼，仍然依赖于一个浮游幼虫阶段，其特点是专业化（育雏），最大限度地减少过度分散和最大限度地恢复到沿岸的栖息地。
The air-breathing fishes have heuristic importance as possible models for the Paleozoic evolution of vertebrate air breathing and the transition to land. A recent hypothesis about this transition suggests that the diverse assemblage of marine amphibious fishes occurring primarily in tropical, high intertidal zone habitats are analogs of early tetrapods and that the intertidal zone, not tropical freshwater lowlands, was the springboard habitat for the Devonian land transition by vertebrates. Here we argue that selection pressures imposed by life in the intertidal zone are insufficient to have resulted in the requisite aerial respiratory capacity or the degree of separation from water required for the vertebrate land transition. The extant marine amphibious fishes, which occur mainly on rocky shores or mudflats, have reached the limit of their niche expansion onto land and remain tied to water by respiratory structures that are less efficient in air and more vulnerable to desiccation than lungs. We further argue that evolutionary contingencies actuated by the Devonian origin of the tetrapods marked a critical point of divergence for a way of life in which selection pressures would operate on the physiology, morphology, and natural history of the different vertebrate groups. While chronically hypoxic and shallow water conditions in the habitats of some primitive bony fishes and some amphibians appear similar to the conditions that prevailed in the Devonian, markedly different selection pressures have operated on other amphibians and bony fishes over the 300 million years since the vertebrate land transition. For example, both egg development and larval metamorphosis in extant amphibians are geared mainly toward compensating for the uncertainty of habitat water quality or even the absence of water by minimizing the time required to develop there. In contrast, reproduction by most intertidal ( and amphibious) fishes, all of which are teleosts, remains dependent on a planktonic larval phase and is characterized by specializations ( brooding) that minimize overdispersal and maximize recruitment back to the littoral habitat.