Grandcolas Philippe, Nattier Romain, Legendre Frédéric, Pellens Roseli
UMR 7205 CNRS, Département Systématique et Evolution, Muséum national d'Histoire naturelle, CP 50, 45 rue Buffon, 75005 Paris, France.
Cladistics. 2011 Apr;27(2):181-185. doi: 10.1111/j.1096-0031.2010.00324.x.
An increasing variety of extrinsic traits are used in comparative studies aimed at testing evolutionary hypotheses. After briefly reviewing the relevant literature, it appears that three different problems are implied by this trend. Some extrinsic traits are only surrogates for phenotypic traits, and should be redefined to better fit the requisites for phylogenetic analysis, such as selective regimes and extinction risks. Some others are already adequately defined and cannot be made less extrinsic, such as taxon age, geographical distribution, associates (parasites, symbionts, etc.), and bioclimatic modelled niches. Because they are not heritable, they should not be analysed by optimization onto a tree, but are better considered in sister-group comparisons or within a reconciliation procedure, as already done for areas of biogeography. © The Willi Hennig Society 2010.
在旨在检验进化假说的比较研究中，越来越多的外在性状被采用。在简要回顾相关文献后，这种趋势似乎隐含着三个不同的问题。一些外在性状只是表型性状的替代物，应该重新定义以更好地符合系统发育分析的要求，比如选择机制和灭绝风险。其他一些性状已经有了充分的定义，并且无法变得不那么外在，比如分类单元年龄、地理分布、关联物种（寄生虫、共生体等）以及生物气候模型生态位。由于它们不可遗传，所以不应通过在树上进行优化分析，而更适合在姐妹群比较中或在一种协调程序中加以考虑，就像生物地理学领域已经做的那样。© 威利·亨尼希学会 2010 年。
