O'Grady P M, Durando C M, Heed W B, Wasserman M, Etges W, Desalle R
American Museum of Natural History, Division of Invertebrate Zoology, Central Park West @ 79th St, New York, NY 10024, USA.
Hereditas. 2002;136(3):240-5.
The mayaguana triad of the Drosophila repleta species group includes D. mayaguana, D. straubae, and D. parisiena, the latter two of which are very similar when examined morphologically. Many morphological characters used to define these taxa are quantitative and overlap substantially among some forms--it is only through suites of such characters that species can be identified. We apply Population Aggregation Analysis and tree building methods to five rapidly evolving gene regions--the mitochondrial AT rich region and the nuclear acetylcholinesterase, hunchback, mastermind, and vestigial loci to test the morphological species delineations within the morphocryptic mayaguana triad. We find that D. mayaguana is diagnosable using DNA sequences, but the other two species form a non-diagnosable paraphyletic assemblage. A single ecological factor, oviposition substrate, is an important diagnostic character distinguishing D. straubae from D. parisiena, highlighting the importance of examining a diverse array of data (morphological, molecular, ecological, and behavioral) when defining species limits.
果蝇复变种类群的马亚瓜纳三联体包括马亚瓜纳果蝇、斯特劳贝果蝇和巴黎果蝇，后两者在形态学检查时非常相似。许多用于定义这些分类单元的形态特征是定量的，并且在某些形态之间有很大的重叠——只有通过这样一系列特征才能识别物种。我们将种群聚集分析和建树方法应用于五个快速进化的基因区域——线粒体富含AT的区域以及核乙酰胆碱酯酶、驼背蛋白、主谋蛋白和残翅基因座，以测试形态隐秘的马亚瓜纳三联体内的形态物种划分。我们发现，使用DNA序列可以诊断出马亚瓜纳果蝇，但其他两个物种形成了一个无法诊断的并系类群。一个单一的生态因素，即产卵基质，是区分斯特劳贝果蝇和巴黎果蝇的重要诊断特征，这突出了在定义物种界限时检查各种数据（形态学、分子、生态和行为）的重要性。
