A tale of two analyses: estimating the consequences of shifts in hexapod diversification
A tale of two analyses: estimating the consequences of shifts in hexapod diversification
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DOI：
10.1046/j.1095-8312.2003.00217.x
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发表时间：
2003-09-01
影响因子：
1.9
通讯作者：
Mayhew, PJ
中科院分区：
文献类型：
--
作者：
Mayhew, PJ
我提出了一种新的描述性（非统计）的方法，以帮助确定的位置和重要性的变化，在多元化的整个发展史。该方法首先估计辐射率终端较高的类群，然后这些利率的简约性分析在整个生育期。重建定义的规模，方向和影响力的过去的变化，实现多样化率跨节点。我将该方法应用于现存六足目的数据。结果表明，鞘翅目（甲虫）和双翅目（蝇类）对物种多样性的上升趋势有很大贡献，如果没有这两种物种，全球物种丰富度将分别减少20%和6%。新翅目（昆虫与翅膀弯曲）的起源，确定其他地方作为一个显着的辐射，可能代表一个大的积极，一个大的负面或零影响目前的物种丰富度，这取决于假设的共生和简约的方法。最有影响力的辐射是由于Eumetopa（昆虫与完全变态加上错误和他们的亲戚）和翼（有翅膀的昆虫）的起源，但目前只有微弱的证据表明，他们代表了潜在的多样化趋势的重大变化。这些分析支持一些，但不是所有的结果，以前的系统发育分析和身份的最重要的转变，因此仍然难以捉摸。可能需要采用新的方法，对多个分类群进行比较。(C)2003年，伦敦林奈学会。
I present a novel descriptive (non-statistical) method to help identify the location and importance of shifts in diversification across a phylogeny. The method first estimates radiation rates across terminal higher taxa and then subjects these rates to a parsimony analysis across the phylogeny. The reconstructions define the magnitude, direction and influence of past shifts in realized diversification rates across nodes. I apply the method to data on the extant hexapod orders. The results indicate that the Coleoptera (beetles) and Diptera (flies) have contributed large upward shifts in diversification tendency, without which, under the model employed, global species richness would be reduced by 20% and 6%, respectively. The origin of Neoptera (insects with wing flexion), identified elsewhere as a significant radiation, may represent a large positive, a large negative or zero influence on current species richness, depending on the assumed phylogeny and parsimony method. The most influential radiations are attributable to the origin of the Eumetabola (insects with complete metamorphosis plus bugs and their relatives) and Pterygota (winged insects), but there is presently only weak evidence that they represent significant shifts in underlying diversification tendency. These analyses support some but not all results of previous phylogenetic analyses and the identity of the most important shift therefore remains elusive. New methodology involving comparisons across multiple taxa is likely to be necessary. (C) 2003 The Linnean Society of London.