The complex effects of mass extinctions on morphological disparity.
The complex effects of mass extinctions on morphological disparity.
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大规模灭绝对形态差异的复杂影响。
DOI：
10.1111/evo.14078
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Puttick MN
中科院分区：
文献类型：
--
作者：
Puttick MN
60多年来，对深部生物多样性的研究一直是生物学家和古生物学家的主要任务。对物种丰富度(多样性)的调查显示，在过去的5亿年里，至少有五次大规模灭绝，每一次都见证了相当大比例的当代类群的迅速消亡。与多样性相反，形态多样性(差异)对大规模灭绝的反应尚不清楚。一般来说，多样性和差异是分离的，因此多样性可能会随着形态差异的增加而下降，反之亦然。在这里，我们使用连续性状和生死树来模拟大灭绝期间的差异变化。我们没有发现大灭绝后差异变化的简单零，但确实观察到了一般模式。特征值的范围随着随机或特征选择性的大规模灭绝而减小，而方差和形态空间占据的密度只在特征选择性事件之后才下降。一般趋势可能会区分随机灭绝和特征选择性灭绝，但方法很难确定特征选择性。大规模灭绝特征选择性的长期效应改变了对系统发育比较方法的支持，从模拟的布朗运动转向Ornstein-Uhlenbeck和早期的爆发模型。我们发现，通过量化形态空间占据的多个方面来研究大规模灭绝的形态变化是最好的。
Studies of biodiversity through deep time have been a staple for biologists and paleontologists for over 60 years. Investigations of species richness (diversity) revealed that at least five mass extinctions punctuated the last half billion years, each seeing the rapid demise of a large proportion of contemporary taxa. In contrast to diversity, the response of morphological diversity (disparity) to mass extinctions is unclear. Generally, diversity and disparity are decoupled, such that diversity may decline as morphological disparity increases, and vice versa. Here, we develop simulations to model disparity changes across mass extinctions using continuous traits and birth-death trees. We find no simple null for disparity change following a mass extinction but do observe general patterns. The range of trait values decreases following either random or trait-selective mass extinctions, whereas variance and the density of morphospace occupation only decline following trait-selective events. General trends may differentiate random and trait-selective mass extinctions, but methods struggle to identify trait selectivity. Long-term effects of mass extinction trait selectivity change support for phylogenetic comparative methods away from the simulated Brownian motion toward Ornstein-Uhlenbeck and Early Burst models. We find that morphological change over mass extinction is best studied by quantifying multiple aspects of morphospace occupation.