Telford Maximilian J, Budd Graham E, Philippe Hervé
Department of Genetics, Evolution and Environment, University College London, WC1E 6BT, UK.
Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, 75236 Uppsala, Sweden.
Curr Biol. 2015 Oct 5;25(19):R876-87. doi: 10.1016/j.cub.2015.07.060.
Animals make up only a small fraction of the eukaryotic tree of life, yet, from our vantage point as members of the animal kingdom, the evolution of the bewildering diversity of animal forms is endlessly fascinating. In the century following the publication of Darwin's Origin of Species, hypotheses regarding the evolution of the major branches of the animal kingdom - their relationships to each other and the evolution of their body plans - was based on a consideration of the morphological and developmental characteristics of the different animal groups. This morphology-based approach had many successes but important aspects of the evolutionary tree remained disputed. In the past three decades, molecular data, most obviously primary sequences of DNA and proteins, have provided an estimate of animal phylogeny largely independent of the morphological evolution we would ultimately like to understand. The molecular tree that has evolved over the past three decades has drastically altered our view of animal phylogeny and many aspects of the tree are no longer contentious. The focus of molecular studies on relationships between animal groups means, however, that the discipline has become somewhat divorced from the underlying biology and from the morphological characteristics whose evolution we aim to understand. Here, we consider what we currently know of animal phylogeny; what aspects we are still uncertain about and what our improved understanding of animal phylogeny can tell us about the evolution of the great diversity of animal life.
动物仅占真核生物生命之树的一小部分，然而，从我们作为动物王国成员的有利视角来看，动物形态令人眼花缭乱的多样性的演化一直有着无尽的魅力。在达尔文的《物种起源》出版后的一个世纪里，关于动物王国主要分支的演化假说——它们彼此之间的关系以及身体结构的演化——是基于对不同动物类群的形态和发育特征的考量。这种基于形态学的方法取得了许多成功，但进化树的重要方面仍存在争议。在过去三十年里，分子数据，最明显的是DNA和蛋白质的一级序列，提供了一个很大程度上独立于我们最终想要理解的形态演化的动物系统发育估计。在过去三十年里发展起来的分子进化树极大地改变了我们对动物系统发育的看法，并且进化树的许多方面不再有争议。然而，分子研究对动物类群之间关系的关注意味着，这一学科在某种程度上已经与基础生物学以及我们旨在理解其演化的形态特征脱节。在这里，我们思考我们目前对动物系统发育的了解；我们仍不确定的方面以及我们对动物系统发育的更好理解能告诉我们关于动物生命巨大多样性的演化的哪些信息。
