The epitome of hand waving? Larval feeding and hypotheses of metazoan phylogeny
The epitome of hand waving? Larval feeding and hypotheses of metazoan phylogeny
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挥手的缩影？
DOI：
10.1046/j.1525-142x.2000.00063.x
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发表时间：
2000
影响因子：
2.9
通讯作者：
G. Rouse
中科院分区：
文献类型：
--
作者：
G. Rouse
幼虫形态的同源性，特别是它们的取食方式，是最近关于动物系统发育的一些讨论中的一个主要因素。“下游摄食”是两种主要的幼虫摄食方式之一，通常等同于具有被称为原摄食和后摄食的纤毛带的反带系统。本文回顾了幼虫的摄食，并扩展了下游幼虫摄食的同源假设，包括任何涉及原生动物的摄食。人们经常争论说，在螺旋动物中，浮游营养型幼虫使用下游取食是多形的，并且在转化过程中存在偏见，这样，取食的幼虫往往会丢失而不是获得。这些假设是评估使用枝简约的方法，有关螺旋体，Trochozoa，特别是参考多毛纲环节动物。针对下游幼虫摄食缺失的转化中可能存在的偏倚，采用的方法包括：扩展初级同源性论证、倾向于反向的特征重构以及编码为下游幼虫摄食的多态性末端。尽管如此，所有的分析都表明，下游幼虫的摄食似乎是从卵磷脂营养状态进化而来的。这些结果支持了一个结论，即原始动物主要是运动动物，并与多次进食联系在一起。基于下游取食的幼虫是半形性的假设的后生动物系统发育的假设被重新评估。
SUMMARY The homology of larval forms, and particularly their feeding methods, has been a major element in some recent discussions about animal phylogeny. “Downstream feeding” is one of two main larval‐feeding modes and is usually equated to an opposed‐band system with ciliary bands called the prototroch and metatroch. Feeding in larvae is reviewed here and the homology hypothesis of downstream larval feeding is expanded, encompassing any feeding involving the prototroch. It is often argued that the presence of planktotrophic larvae using downstream feeding is plesiomorphic among spiralian animals, and that there is a bias in transformations, such that feeding larvae tend to be lost rather than gained. These hypotheses are assessed using cladistic parsimony methodology, in relation to Spiralia, Trochozoa, and with particular reference to polychaete annelids. Methods adopted for the possibility of a bias in transformations toward loss of downstream larval feeding include: expanded primary homology arguments, character reconstructions favoring reversals, and polymorphic terminals coded as having downstream larval feeding. Nevertheless, all analyses show that downstream larval feeding appears to have evolved multiple times from a lecithotrophic condition. The results support a conclusion that the prototroch was primarily locomotory, and has become associated with feeding a number of times. Hypotheses of metazoan phylogeny predicated on the assumption that downstream‐feeding larvae are plesiomorphic are re‐assessed.
影响因子：
4
作者：
Peterson, KJ;Cameron, RA;Davidson, EH
通讯作者：
Davidson, EH