USING CLADISTIC CHARACTERS TO PREDICT FUNCTIONAL VARIETY: EXPERIMENTS USING EARLY GNATHOSTOMES
USING CLADISTIC CHARACTERS TO PREDICT FUNCTIONAL VARIETY: EXPERIMENTS USING EARLY GNATHOSTOMES
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DOI：
10.1080/02724634.2012.694386
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发表时间：
2012-01-01
影响因子：
1.4
通讯作者：
Friedman, Matt
中科院分区：
文献类型：
--
作者：
Anderson, Philip S. L.;Friedman, Matt
越来越多的古生物学研究使用预先存在的分支数据集来估计随时间变化的形态差异水平，并调查在多元形态空间内的类群的相对位置。虽然这些模式是从选择重建系统发育关系的字符，它有时建议，他们也反映了功能或生态变化。我们使用专门构建的功能性下颌骨特征矩阵和24个已发表的针对早期有颌脊椎动物的分支矩阵来测试这一论断。我们发现，从功能和支序数据计算的距离矩阵显着相关，但在功能相异性的实质性变化无法解释的支序相异性的变化。当分支特征仅限于头骨和下颌骨相关特征时，一致性会依次提高，但不会大幅提高。当相异性矩阵进行主坐标分析，以产生多变量形态空间，我们发现没有明确的关系，在较低的功能和支序坐标轴上的分数遗传独立的对比。然而，我们确实发现，大多数的变化的第一轴上的命令的基础上的支序特征可以解释的同源性，即使距离矩阵的基础上这些命令是表型。一个restrial程序揭示了一个积极的，但弱，分支和功能差异的措施，相当于一套类群之间的相关性。虽然我们的研究结果显示非随机的差异模式提取的功能和分支特征集之间的关系，我们的结论是，这些关系是不够强大，让清晰的推论功能变异从数据组装系统发育重建。
An increasing number of paleobiological studies use preexisting cladistic data sets to estimate shifting levels of morphological disparity over time, and investigate the relative positions of taxa within a multivariate morphospace. Although these patterns are derived from characters selected to reconstruct phylogenetic relationships, it is sometimes suggested that they also reflect functional or ecological variation. We test this assertion using a purpose-built matrix of functional mandibular traits and 24 published cladistic matrices targeting early jawed vertebrates. We find that distance matrices calculated from functional and cladistic data are significantly correlated, but that substantial variation in functional dissimilarity goes unexplained by variation in cladistic dissimilarity. Agreement sequentially improves, but not drastically, when cladistic characters are limited to those pertaining to the skull and then mandible. When dissimilarity matrices are subjected to principal coordinate analysis to yield multivariate morphospaces, we find no clear relationship between phylogenetically independent contrasts for scores on lower functional and cladistic coordinate axes. However, we do find that a majority of variation on the first axis of ordinations based on cladistic characters can be explained by phylogeny, even though the distance matrices underlying these ordinations are phenetic. A resampling procedure reveals a positive, but weak, correlation between cladistic and functional disparity measures for equivalent sets of taxa. Although our results show nonrandom relationships between disparity patterns extracted from functional and cladistic character sets, we conclude that these relationships are not sufficiently strong to allow clear inferences about functional variation to be drawn from data assembled for phylogenetic reconstruction.