The origin of modern amphibians: a re-evaluation
The origin of modern amphibians: a re-evaluation
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现代两栖动物的起源：重新评估
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
D. Green
中科院分区：
文献类型：
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作者：
T. Sigurdsen;D. Green
目前有三种相互竞争的假说试图解释现代两栖动物的进化起源。Lepospondylhypothesis认为，lysorophianlepospondyls构成了所有lissamphibians的姐妹分类单元。temnospondyl假说认为现代两栖动物与dissorophoid temnospondyls关系最为密切。最后，多系假说认为现代两栖目有着独立的演化起源，来自古生代四足动物的不同类群。在这里，我们回顾了以前的研究中使用的字符矩阵。这些数据集在字符的选择上有很大的不同。因此，我们建立了一个矩阵的基础上，从所有三个假设的数据和分析关键类群遗传贝叶斯推理和简约。未经校正，超矩阵产生了不确定的结果，证明存在至少两个系统发育最佳。当根据对Doleserpeton、Eocaecilia和其他化石形式的新观察对数据进行校正时，化石发生支持了lissampibian起源的temnospondyl假设。这一结论也得到了仔细研究个人血统性格变化的支持。
There are currently three competing hypotheses seeking to explain the evolutionary origins of modern amphibians. The lepospondyl hypothesis holds that the lysorophian lepospondyls constitute the sister taxon to all lissamphibians. The temnospondyl hypothesis suggests that modern amphibians are most closely related to the dissorophoid temnospondyls. Finally, the polyphyletic hypothesis posits that the modern amphibian orders have separate evolutionary origins from among different groups of Palaeozoic tetrapods. Here, we review the character matrices used in previous studies. These data sets differ significantly in choice of characters. Therefore, we built a matrix based on data from all three hypotheses and analysed key taxa phylogenetically using both Bayesian inference and parsimony. Uncorrected, the supermatrix yielded inconclusive results, demonstrating the presence of at least two phylogenetic optima. When the data were corrected according to new observations on Doleserpeton, Eocaecilia, and other fossil forms, the phylogeny supported the temnospondyl hypothesis of lissamphibian origins. This conclusion is also supported by a careful study of character changes in the individual lineages.