Department of Biology, University of California, Riverside, CA 92521, USA.
Mol Phylogenet Evol. 2013 Feb;66(2):479-506. doi: 10.1016/j.ympev.2012.10.012. Epub 2012 Oct 26.
The emergence of Cetacea in the Paleogene represents one of the most profound macroevolutionary transitions within Mammalia. The move from a terrestrial habitat to a committed aquatic lifestyle engendered wholesale changes in anatomy, physiology, and behavior. The results of this remarkable transformation are extant whales that include the largest, biggest brained, fastest swimming, loudest, deepest diving mammals, some of which can detect prey with a sophisticated echolocation system (Odontoceti - toothed whales), and others that batch feed using racks of baleen (Mysticeti - baleen whales). A broad-scale reconstruction of the evolutionary remodeling that culminated in extant cetaceans has not yet been based on integration of genomic and paleontological information. Here, we first place Cetacea relative to extant mammalian diversity, and assess the distribution of support among molecular datasets for relationships within Artiodactyla (even-toed ungulates, including Cetacea). We then merge trees derived from three large concatenations of molecular and fossil data to yield a composite hypothesis that encompasses many critical events in the evolutionary history of Cetacea. By combining diverse evidence, we infer a phylogenetic blueprint that outlines the stepwise evolutionary development of modern whales. This hypothesis represents a starting point for more detailed, comprehensive phylogenetic reconstructions in the future, and also highlights the synergistic interaction between modern (genomic) and traditional (morphological+paleontological) approaches that ultimately must be exploited to provide a rich understanding of evolutionary history across the entire tree of Life.
在古近纪，鲸类的出现代表了哺乳动物中最深刻的宏观进化转变之一。从陆地栖息地到完全水生的生活方式的转变，引发了解剖学、生理学和行为的全面变化。这种显著转变的结果是现存的鲸鱼，包括最大、最大脑、最快游泳、最响亮、最深潜水的哺乳动物，其中一些可以通过复杂的回声定位系统（齿鲸）检测猎物，而另一些则使用鲸须架批量进食（须鲸）。一个广泛的重建，最终导致现存的鲸类，还没有基于基因组和古生物学信息的整合。在这里，我们首先将鲸类相对于现生哺乳动物的多样性进行定位，并评估分子数据集在偶蹄目（包括鲸类）内关系分布的支持程度。然后，我们合并来自三个大型分子和化石数据联合的树，以产生一个综合假设，涵盖了鲸类进化历史中的许多关键事件。通过结合多种证据，我们推断出一个进化蓝图，概述了现代鲸鱼的逐步进化发展。这个假设为未来更详细、更全面的系统发育重建提供了一个起点，也突出了现代（基因组）和传统（形态学+古生物学）方法之间的协同作用，最终必须利用这些方法来提供对整个生命之树的进化历史的丰富理解。
