A group of organisms of any taxonomic rank that are believed to be descended from a common ancestor (see monophyletic). In an ideal natural classification all taxa should be natural groups. See also cladistics.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。