鸟类分子系统学新进展

NEW PROGRESS IN AVIAN MOLECULAR PHYLOGENETICS

由于鸟类经历了一个古老而快速的分化,且以往的分类学研究多以形态学和化石记录为基础,分类学家对其系统发育了解很少.最近的分子系统发育研究表明:鸟类进化树上只有古颚总目和今颚总目之间的分化、鸡雁小纲和新鸟下纲的分化2个节点始终得到分子和形态证据的一致支持;分子研究支持新鸟下纲的白垩纪起源,反对化石记录支持新生代起源.但在最新的系统发育树中,大部分鸟类目之间的亲缘关系仍有待确定.今后应该增强鸟类分子进化的研究,并与形态学、古生物学研究相整合,以期完善鸟类的系统学.

Although aves underwent ancient but rapid diversification,previous taxonomic studies based on morphology and fossil records were rather limited,with little known of avian phylogeny.Recent molecular phylogenetic studies revealed only two nodes in the avian tree,consistently supported by both molecular and morphological evidence.The first node divided Paleognathae and Neognathae,the second node split neognaths into Galloanserae and Neoaves.Molecular studies also supported a Cretaceous origin of Neoaves,against a Cenozoic origin based on fossil record.Even in a recent phylogenetic study,higher-order phylogeny of Neoaves remained to be resolved.To complement avian phylogenetics works,molecular evolution and systematic studies should be promoted,and integrated with morphology and paleontological studies.