Organ Chris L, Schweitzer Mary H, Zheng Wenxia, Freimark Lisa M, Cantley Lewis C, Asara John M
Harvard University, Cambridge, MA 02138, USA.
Science. 2008 Apr 25;320(5875):499. doi: 10.1126/science.1154284.
We report a molecular phylogeny for a nonavian dinosaur, extending our knowledge of trait evolution within nonavian dinosaurs into the macromolecular level of biological organization. Fragments of collagen alpha1(I) and alpha2(I) proteins extracted from fossil bones of Tyrannosaurus rex and Mammut americanum (mastodon) were analyzed with a variety of phylogenetic methods. Despite missing sequence data, the mastodon groups with elephant and the T. rex groups with birds, consistent with predictions based on genetic and morphological data for mastodon and on morphological data for T. rex. Our findings suggest that molecular data from long-extinct organisms may have the potential for resolving relationships at critical areas in the vertebrate evolutionary tree that have, so far, been phylogenetically intractable.
我们报告了一种非鸟类恐龙的分子系统发育情况，将我们对非鸟类恐龙性状进化的认识扩展到了生物组织的大分子水平。从霸王龙和美洲乳齿象（乳齿象）的化石骨骼中提取的胶原蛋白α1（I）和α2（I）蛋白片段，用多种系统发育方法进行了分析。尽管缺少序列数据，但乳齿象与大象归为一类，霸王龙与鸟类归为一类，这与基于乳齿象的遗传和形态数据以及霸王龙的形态数据所做的预测一致。我们的研究结果表明，来自早已灭绝生物的分子数据可能有潜力解决脊椎动物进化树中关键区域的关系问题，而这些区域迄今为止在系统发育上是难以处理的。
