Fossils and phylogenies: integrating multiple lines of evidence to investigate the origin of early major metazoan lineages
Fossils and phylogenies: integrating multiple lines of evidence to investigate the origin of early major metazoan lineages
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DOI：
10.1093/icb/icm071
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发表时间：
2007-11-01
影响因子：
2.6
通讯作者：
Collins, Allen
中科院分区：
文献类型：
--
作者：
Cartwright, Paulyn;Collins, Allen
了解后生动物起源的性质和时间是进化生物学中最重要但又最难以捉摸的问题之一。化石数据为早期动物谱系的起源提供了最切实的证据，尽管来自分子生物遗传学、分子钟研究和发展的其他证据也有助于我们目前的理解。我们回顾了几条证据线，探索早期后生动物进化的性质和时间，并讨论这些数据，当考虑在一起，提供了一个更有凝聚力的图片的起源动物多样性。我们讨论了如何痕迹化石和生物标志物提供令人信服的证据的起源Bilateria和硅质海绵。使用后生动物的分子系统发育框架，我们讨论了如何化石可以用来确定起源的分支。我们使用这些化石的日期进行宽松的分子钟分析，估计节点的日期时，没有化石。我们还讨论了目前的数据，从发育生物学表明，早期后生动物拥有一个复杂的分子工具包，建立复杂的身体计划。我们的结论是，最好的证据的起源主要后生动物的血统在于仔细解释的化石记录，这些数据，当考虑到系统发育和发展的证据，支持的概念，寒武纪辐射是一个真实的现象，标志着一个至关重要的时间在生命的历史。
Understanding the nature and timing of metazoan origins is one of the most important, yet elusive, questions in evolutionary biology. Fossil data provide the most tangible evidence for the origin of early animal lineages, although additional evidence from molecular phylogenetics, molecular clock studies, and development has contributed to our current understanding. We review several lines of evidence to explore the nature and timing of early metazoan evolution and discuss how these data, when considered together, provide a more cohesive picture of the origin of animal diversity. We discuss how trace fossils and biomarkers provide compelling evidence for the origins of Bilateria and siliceous sponges. Using a molecular phylogenetic framework for metazoans, we discuss how fossils can be used to date the origin of clades. We use these fossil dates to perform a relaxed molecular clock analysis for estimating dates of nodes when no fossils are available. We also discuss current data from developmental biology that suggest that early metazoans possessed a sophisticated molecular toolkit for building complex body plans. We conclude that the best evidence for the origin of major metazoan lineages lies in the careful interpretation of the fossil record and that these data, when considered with phylogenetic and developmental evidence, support the notion that the Cambrian radiation is a real phenomenon that marks a critically important time in the history of life.