THE PROGRESS IN THE STUDY OF PHYLOGENY OF ARTHROPODA
XIE Qiang BU Wen-Jun(Department of Biology, Life Sciences College, Nankai University, Tianjin 300071; firstname.lastname@example.org) LI Xin-Zheng(Institute of Oceanology, Chinese Academy of Sciences, Qingdao, Shandong 266071) ZHENG Le-Yi(Department o
More and more domestic scholars pay attention to the phylogeny of arthropods recently. This paper focuses on three issues: the relationships between Arthropoda and its kin phyla, the monophyly of Arthropoda, and the relationships among the groups within Arthropoda, with emphasis on the relationships between Hexapoda, Crustacea, and Myriapoda. Many recent studies showed that Tardigrada, Nematoda and Onychophora are the three closest groups of Arthropoda in systematics, rather than Annelida and Mollusca, which were traditionally considered. Other than that, this progress will make some impact on the relationships between the main groups of Arthropoda due to the use of different outgroups in phylogenetic research. Both the problems of the monophyly of Arthropoda and the relationships between the groups within Arthropoda have been debated for many years. Now the dominant views are that (1)Arthropoda is a monophyletic group; (2)Mandibulata, composed of Crustacea, Hexapoda and Myriapoda, is a good monophyletic group, and (3)Crustacea, not Myriapoda, is the closest kin of Hexapoda. Besides these three major issues, the position of Onychophora in the invertebrates and the monophyly of Crustacea and Myriapoda, are also discussed in this paper.Table 1 The progress in the study of the molecular systematics of Arthropoda from 1998 till now [BHDFG3,WK10ZQ,WK9ZQ,WKZQW]author and yearmolecule marksThe phylogeny hypothesis among the main ingroups of ArthropodaGiribet et al.(1998, 1999)18SrDNA(((Hex+Cru)+Myr)+Man)Shultz Regier (2000)EF-1α Pol Ⅱ gene (((Hex+Cru)+Myr)+Man)or(((Hex+Cru)+Man)+Myr)Regier Shultz (2001)EF-2 gene(((Hex+Cru)+Man)+Myr)Friedrich Tautz (1995, 2001)18S 28S rDNA((Hex+Cru)+(Myr+Man))Giribet et al.(2001)18S rDNA et al. 8 loci altogether(((Hex+Cru)+Myr)+Man) Note: Hex stands for Hexpoda, Cru for Crustacea, Myr for Myriapoda and Man for Mandibulata.