Sequence-based species delimitation for the DNA taxonomy of undescribed insects
Sequence-based species delimitation for the DNA taxonomy of undescribed insects
复制标题
DOI：
10.1080/10635150600852011
复制
发表时间：
2006-08-01
影响因子：
6.5
通讯作者：
Vogler, Alfried P.
中科院分区：
文献类型：
--
作者：
Pons, Joan;Barraclough, Timothy G.;Vogler, Alfried P.
基于DNA的自动化方法可以大大加快对大量未描述昆虫物种的编目，但目前缺乏从序列数据中发现大规模物种的程序。在这里，我们使用线粒体DNA的变化来界定物种在一个鲜为人知的甲虫辐射在属Rivacinalgae从干旱的澳大利亚。从65个地点和多个形态上可区分的类型中取样的468个个体中，三个mtDNA基因（细胞色素氧化酶亚基1、细胞色素B、16 S核糖体RNA）的序列变异强烈地划分在46或47个推定的种之间，所述种识别的定量方法基于固定的唯一（“诊断”）特征。组之间的边界也可以从时钟约束校准树的分支率显著增加中识别出来。随机谱系增长模型（Yule模型）与聚结理论相结合，开发了一种新的似然方法，确定从物种水平（物种形成和灭绝）到种群水平（聚结）进化过程的过渡点。拟合的位置的开关从物种形成到合并节点上的超度量树Rivacinhalo产生的分支率发生在0.43兆年的过渡，导致估计48个推定的物种（置信区间的阈值范围从47到51集群内2 logL单位）。以这种方式界定的实体表现出传统定义的物种的生物学特性，表现出地理范围的一致性，与形态学上公认的物种的广泛一致性，以及密切相关的昆虫物种的典型序列分歧水平。发现不连续的进化分组是显而易见的序列变异的模式，允许在很大程度上自动化的物种划分从DNA调查的当地社区作为一个支架，在这个鲜为人知的昆虫群的分类。[系统发生种概念;聚结; mtDNA;蝉科;澳大利亚;古气候。]
Cataloging the very large number of undescribed species of insects could be greatly accelerated by automated DNA based approaches, but procedures for large-scale species discovery from sequence data are currently lacking. Here, we use mitochondrial DNA variation to delimit species in a poorly known beetle radiation in the genus Rivacindela from arid Australia. Among 468 individuals sampled from 65 sites and multiple morphologically distinguishable types, sequence variation in three mtDNA genes (cytochrome oxidase subunit 1, cytochrome b, 16S ribosomal RNA) was strongly partitioned between 46 or 47 putative species identified with quantitative methods of species recognition based on fixed unique ("diagnostic") characters. The boundaries between groups were also recognizable from a striking increase in branching rate in clock-constrained calibrated trees. Models of stochastic lineage growth (Yule models) were combined with coalescence theory to develop a new likelihood method that determines the point of transition from species-level (speciation and extinction) to population-level (coalescence) evolutionary processes. Fitting the location of the switches from speciation to coalescent nodes on the ultrametric tree of Rivacindela produced a transition in branching rate occurring at 0.43 Mya, leading to an estimate of 48 putative species (confidence interval for the threshold ranging from 47 to 51 clusters within 2 logL units). Entities delimited in this way exhibited biological properties of traditionally defined species, showing coherence of geographic ranges, broad congruence with morphologically recognized species, and levels of sequence divergence typical for closely related species of insects. The finding of discontinuous evolutionary groupings that are readily apparent in patterns of sequence variation permits largely automated species delineation from DNA surveys of local communities as a scaffold for taxonomy in this poorly known insect group. [Phylogenetic species concept; coalescence; mtDNA; Cicindelidae; Australia; paleoclimate.]