O'Grady P M, Clark J B, Kidwell M G
Program in Genetics, University of Arizona, Tucson 85721, USA.
Mol Biol Evol. 1998 Jun;15(6):656-64. doi: 10.1093/oxfordjournals.molbev.a025969.
Nucleotide sequences from two nuclear loci, alcohol dehydrogenase and internal transcribed spacer-1 of the nuclear ribosomal DNA repeats, and two mitochondrial genes, cytochrome oxidase I and cytochrome oxidase II, were determined from nine species in the Drosophila saltans species group. The partition homogeneity test and partitioned Bremer support were used to measure incongruence between phylogenetic hypotheses generated from individual partitions. Individual loci were generally congruent with each other and consistent with the previously proposed morphological hypothesis, although they differed in level of resolution. Since extreme conflict between partitions did not exist, the data were combined and analyzed simultaneously. The total evidence method gave a more resolved and highly supported phylogeny, as indicated by bootstrap proportions and decay indices, than did any of the individual analyses. The cordata and elliptica subgroups, considered to have diverged early in the history of the D. saltans group, were sister taxa to the remainder of the saltans group. The sturtevanti subgroup, represented by D. milleri and D. sturtevanti, occupies an intermediate position in this phylogeny. The saltans and parasaltans subgroups are sister clades and occupy the most recently derived portion of the phylogeny. As with previous morphological studies, phylogenetic relationships within the saltans subgroup were not satisfactorily resolved by the molecular data.
测定了果蝇盐沼种组9个物种的两个核基因座（乙醇脱氢酶和核糖体DNA重复序列的内转录间隔区-1）以及两个线粒体基因（细胞色素氧化酶I和细胞色素氧化酶II）的核苷酸序列。采用分区同质性检验和分区布雷默支持度来衡量由各个分区产生的系统发育假设之间的不一致性。尽管各个基因座的分辨率不同，但它们总体上相互一致，并且与先前提出的形态学假设相符。由于各分区之间不存在极端冲突，因此将数据合并并同时进行分析。与任何单独分析相比，总证据法得出的系统发育关系更具分辨率且得到了高度支持，自展比例和衰减指数均表明了这一点。被认为在果蝇盐沼种组历史早期就已分化的科达塔亚组和椭圆亚组，是盐沼种组其余部分的姐妹类群。以米勒果蝇和斯特蒂文特果蝇为代表的斯特蒂文特亚组在这一系统发育中占据中间位置。盐沼亚组和副盐沼亚组是姐妹分支，占据了系统发育中最新分化出来的部分。与之前的形态学研究一样，分子数据未能令人满意地解析盐沼亚组内的系统发育关系。
