Fossils provide better estimates of ancestral body size than do extant taxa in fishes
Fossils provide better estimates of ancestral body size than do extant taxa in fishes
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DOI：
10.1111/j.1463-6395.2008.00364.x
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发表时间：
2009-05-01
期刊：
影响因子：
1.2
通讯作者：
Knouft, Jason H.
中科院分区：
文献类型：
--
作者：
Albert, James S.;Johnson, Derek M.;Knouft, Jason H.
利用化石研究性格进化是一个活跃的研究领域。化石中的特征被认为比现存分类群中的可比信息更少或更主观。然而，化石通常是许多高等分类群的唯一已知代表，包括一些最早的形式，并且在确定性格极性和填补形态空白方面非常重要。在这里，我们评估化石的影响，通过比较两个大的和以前未发表的数据集的鱼类（非四足动物）的祖先的身体大小的估计的字符进化的解释;一个古生物学数据集代表所有的主要分支从整个中生代，和一个macroecological数据集的所有515个家庭的生活（最近）的鱼类。祖先大小是根据基于系统发育（即简约）的优化方法估计的。从现存鱼类家族的分析中获得的祖先大小估计值比使用相同高等类群的化石成员的估计值大5到8倍。这些差异来自早期分支谱系的大型成员的差异生存，而不是统计或埋藏文物。从有限的，但明智的选择化石鱼类类群的祖先大小的估计是更准确的估计，从一个完整的数据集现存的鱼类。
The use of fossils in studies of character evolution is an active area of research. Characters from fossils have been viewed as less informative or more subjective than comparable information from extant taxa. However, fossils are often the only known representatives of many higher taxa, including some of the earliest forms, and have been important in determining character polarity and filling morphological gaps. Here we evaluate the influence of fossils on the interpretation of character evolution by comparing estimates of ancestral body size in fishes (non-tetrapod craniates) from two large and previously unpublished datasets; a palaeontological dataset representing all principal clades from throughout the Phanerozoic, and a macroecological dataset for all 515 families of living (Recent) fishes. Ancestral size was estimated from phylogenetically based (i.e. parsimony) optimization methods. Ancestral size estimates obtained from analysis of extant fish families are five to eight times larger than estimates using fossil members of the same higher taxa. These disparities arise from differential survival of large-bodied members of early branching lineages, and are not statistical or taphonomic artefacts. Estimates of ancestral size obtained from a limited but judicious selection of fossil fish taxa are more accurate than estimates from a complete dataset of extant fishes.