Department of Biological Sciences, University of Alberta, 11455 Saskatchewan Drive, Edmonton, Canada.
Zoology (Jena). 2010 Jan;113(1):57-66. doi: 10.1016/j.zool.2009.06.002. Epub 2010 Feb 1.
The evolution of developmental sequences, or sequence heterochrony, is an emerging field of study that addresses the temporal interplay between evolution and development. Some phylogenetic signal has been found in developmental sequence data, but sampling has generally been limited to small numbers of taxa and few developmental events. Here we present the largest ossification sequence dataset to date. The sequences are composed of ossification events throughout the avian skeleton, and are used to address the evolutionary signal of ossification sequence data within this clade. The results indicate that ossification sequences are conserved in birds, and show a stronger phylogenetic signal than previous studies, perhaps due to the volume of data. Phylogenetic signal is not strong enough, however, to consider ossification sequence data to be any better at resolving phylogenetic hypotheses than other morphological data and just as prone to evolutionary convergence. There is no one-to-one correlation between ossification sequence and developmental stage. We discuss some methodological implications of our findings, as well as commonalities in avian ossification sequences such as early ossification of the long bones relative to the dermatocranium, and of the hindlimb over the forelimb.
发育序列的进化，或序列异时性，是一个新兴的研究领域，它探讨了进化和发育之间的时间相互作用。在发育序列数据中已经发现了一些系统发育信号，但采样通常仅限于少数分类群和少数发育事件。在这里，我们展示了迄今为止最大的骨化序列数据集。这些序列由鸟类骨骼中的骨化事件组成，用于解决该分支内骨化序列数据的进化信号。结果表明，鸟类的骨化序列是保守的，并且比以前的研究显示出更强的系统发育信号，这可能是由于数据量较大。然而，系统发育信号还不够强，不足以认为骨化序列数据在解决系统发育假设方面比其他形态数据更好，而且也容易发生进化趋同。骨化序列与发育阶段之间没有一一对应的关系。我们讨论了我们研究结果的一些方法学意义，以及鸟类骨化序列中的一些共同特征，例如长骨相对于皮肤颅骨和后肢相对于前肢的早期骨化。
