Discerning evolutionary processes in patterns of tamarin (genus Saguinus) craniofacial variation
Discerning evolutionary processes in patterns of tamarin (genus Saguinus) craniofacial variation
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DOI：
10.1002/ajpa.10038
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发表时间：
2002-03-01
影响因子：
2.8
通讯作者：
Cheverud, JM
中科院分区：
文献类型：
--
作者：
Ackermann, RR;Cheverud, JM
定量遗传理论规定了在单系进化枝中通过遗传漂变实现形态多样化的进化期望。如果遗传漂变是进化形态多样化的原因，那么分类群内部和分类群之间的形态变异/协方差模式应该是成比例的。我们测试了12种绢毛猴（Saguinus属）种内和种间颅面形态变异的比例性。我们发现，整个属的分类群内和分类群之间的形态变化不是成比例的，因此不太可能仅仅是由于遗传漂变。与比例性的主要偏差是，相对于遗传漂变下的颅骨形态学的其他方面，头盖骨的大小和与大小相关的形状变化更大，这表明两个主要分支——小体和大体绢毛猴之间存在不同的大小选择。在这些主要进化支中，大多数种间变异与遗传漂变下的预期模式一致，尽管特定的对比可能表明差异选择的参与。分类群之间的形态距离与mtDNA衍生的系统发育关系并不十分密切。特别是，俄狄浦斯绢毛猴和geoffroroyi绢毛猴在形态上与其他绢毛猴非常不同，尽管它们在系统发育上是包含midas绢毛猴和bicolor绢毛猴的分支的姐妹分支。形态相似性并不能很好地指导绢毛猴的系统发育亲缘关系，特别是在系统发育树的较深节点上。(C) 2002 Wiley-Liss, Inc。
Quantitative genetic theory specifies evolutionary expectations for morphological diversification by genetic drift in a monophyletic clade. If genetic drift is responsible for the evolutionary morphological diversification of a clade, patterns of within- and between-taxon morphological variance/covariance should be proportional. We tested for proportionality of within- and between-species craniofacial morphological variation in 12 species of tamarins (genus Saguinus). We found that within- and between-taxon morphological variations across the entire genus were not proportional, and hence not likely to be due to genetic drift alone. The primary deviation from proportionality is that size and size-related shape in the cranium is more variable relative to other aspects of cranial morphology than expected under genetic drift, suggesting differential size selection between the two major clades, the small-bodied and large-bodied tamarins. Within each of these major clades, most of the interspecific variation is consistent with the pattern expected under genetic drift, although specific contrasts may indicate the involvement of differential selection. Morphological distances among taxa do not correspond very closely to the phylogeny derived from mtDNA. In particular, S. oedipus and S. geoffroyi are very distinct morphologically from the rest of the tamarins, although they are phylogenetically the sister clade to a clade containing S. midas and S. bicolor. Morphological similarity is not a good guide to phylogenetic affinity in the tamarins, especially with regard to deeper nodes in the phylogenetic tree. (C) 2002 Wiley-Liss, Inc.