A COMPARATIVE-STUDY OF DIVERSIFICATION EVENTS - THE EARLY PALEOZOIC VERSUS THE MESOZOIC
A COMPARATIVE-STUDY OF DIVERSIFICATION EVENTS - THE EARLY PALEOZOIC VERSUS THE MESOZOIC
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DOI：
10.1111/j.1558-5646.1987.tb02459.x
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发表时间：
1987-11-01
期刊：
影响因子：
3.3
通讯作者：
SEPKOSKI, JJ
中科院分区：
文献类型：
--
作者：
ERWIN, DH;VALENTINE, JW;SEPKOSKI, JJ
我们比较了两个主要的长期多样化的海洋动物家庭，开始在低多样性的时期，但产生了显着不同数量的门，类，和订单。第一个是早古生代的多样化（晚文迪-奥陶纪，182 MY的持续时间），另一个是中生代阶段的后古生代的多样化（183 MY的持续时间）。早期的多样化与形态学发明的大爆发有关，产生了许多门、纲和目，并显示出高的科起源的每分类单元率。后来的多样化缺乏新的形态确认为门和类，产生较少的订单，并显示较低的每分类群率的家庭外观。这两种多样性之间的主要区别似乎是，早期的多样性是从适应空间的相对狭窄的部分开始的，而后者是从广泛分布在适应区域中的物种开始的，代表了各种各样的身体计划。人们相信，这种差异可以解释这些大辐射产物的主要差异。我们的数据支持那些认为进化机会是进化过程结果的主要因素的模型。
We compare two major long-term diversifications of marine animal families that began during periods of low diversity but produced strikingly different numbers of phyla, classes, and orders. The first is the early-Paleozoic diversification (late Vendian-Ordovician, 182 MY duration) and the other the Mesozoic phase of the post-Paleozoic diversification (183 MY duration). The earlier diversification was associated with a great burst of morphological invention producing many phyla, classes, and orders and displaying high per taxon rates of family origination. The later diversification lacked novel morphologies recognized as phyla and classes, produced fewer orders, and displayed lower per taxon rates of family appearances. The chief difference between the diversifications appears to be that the earlier one proceeded from relatively narrow portions of adaptive space, whereas the latter proceeded from species widely scattered among adaptive zones and representing a variety of body plans. This difference is believed to explain the major differences in the products of these great radiations. Our data support those models that hold that evolutionary opportunity is a major factor in the outcome of evolutionary processes.