Lane Abigail, Benton Michael J
Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, United Kingdom.
Am Nat. 2003 Sep;162(3):265-76. doi: 10.1086/377188. Epub 2003 Sep 5.
Key aims of recent paleobiological research have been the construction of Phanerozoic global biodiversity patterns and the formulation of models and mechanisms of diversification describing such patterns. Two conflicting theories of global diversification have been equilibrium versus expansionist growth of taxonomic diversity. These models, however, rely on accurate empirical data curves, and it is not clear to what extent the taxonomic level at which the data are analyzed controls the resulting pattern. Global Phanerozoic marine diversity curves are constructed at ordinal, familial, and generic levels using several fossil-range data sets. The fit of a single logistic model reduces from ordinal through familial to generic level, while conversely, that of an exponential growth model increases. Three sequential logistic equations, fitted to three time periods during which diversity appears to approach or reach an equilibrium state, provide the best description of the data at familial and generic levels. However, an exponential growth curve describes the diversification of marine life since the end-Permian extinction equally as well as a logistic. A species-level model of global Phanerozoic marine diversification, constructed by extrapolation of the trends from familial to generic level, suggests growth in numbers of marine species was broadly exponential. When smaller subsets of the data are analyzed, the effect of taxonomic level on the shape of the diversity curve becomes more pronounced. In the absence of species data, a consistent signal at more than one higher taxonomic level is required to predict a species-level pattern.
近期古生物学研究的主要目标是构建显生宙全球生物多样性模式，并阐述描述此类模式的多样化模型和机制。关于全球生物多样化存在两种相互冲突的理论，即分类多样性的平衡增长与扩张增长。然而，这些模型依赖于准确的经验数据曲线，并且尚不清楚分析数据时所采用的分类水平在多大程度上控制了最终的模式。利用多个化石分布数据集，在目、科和属的水平上构建了显生宙全球海洋多样性曲线。单一逻辑斯蒂模型的拟合度从目水平到科水平再到属水平逐渐降低，相反，指数增长模型的拟合度则逐渐增加。三个连续的逻辑斯蒂方程，适用于多样性似乎接近或达到平衡状态的三个时间段，能对科和属水平的数据提供最佳描述。然而，指数增长曲线对二叠纪末大灭绝以来海洋生物多样化的描述与逻辑斯蒂曲线同样出色。通过将科水平到属水平的趋势外推构建的显生宙全球海洋多样化物种水平模型表明，海洋物种数量的增长大致呈指数形式。当分析数据的较小子集时，分类水平对多样性曲线形状的影响变得更加显著。在缺乏物种数据的情况下，需要在一个以上更高分类水平上有一致的信号才能预测物种水平的模式。
