On the causes of mass extinctions
On the causes of mass extinctions
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DOI：
10.1016/j.palaeo.2016.11.005
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发表时间：
2017-07-15
影响因子：
3
通讯作者：
Grasby, Stephen E.
中科院分区：
文献类型：
--
作者：
Bond, David P. G.;Grasby, Stephen E.
大火成岩省（LIP）喷发和中生代至少一半的主要喷发之间的时间联系意味着大规模火山活动是大规模灭绝的主要驱动力。在这里，我们回顾了早寒武世和白垩纪末之间的近20个生物危机，并探讨了潜在的因果机制。大多数的灭绝与全球变暖和海洋缺氧等近源杀手有关（包括早/中寒武世、晚奥陶世、志留纪内、泥盆纪内、二叠纪末和早侏罗世危机）。许多，但不是所有的这些都伴随着大的负碳同位素漂移，支持火山成因。大多数后志留纪的生物危机都影响到陆地和海洋生物圈，这表明大气过程在推动全球变暖方面至关重要。火山-大气杀伤机制包括海洋酸化、有毒金属中毒、酸雨和臭氧破坏以及随之而来的UV-B辐射增加、火山黑暗、冷却和光合作用停止，其中每一种都与许多事件有关。有趣的是，一些体积最大的LIP，如白垩纪的海洋高原，是以最小的动物损失而被侵位的，因此岩浆的体积并不是控制LIP致命性的唯一因素。缺失的环节可能是大陆构造，因为LIP/灭绝关系的最佳例子发生在泛大陆时期。在低密度撞击/灭绝情景中，许多近端杀伤机制也是火流星撞击的潜在影响，包括冷却、升温、酸化和臭氧破坏。然而，除了希克苏鲁伯-白垩纪的例子之外，撞击和喷发之间缺乏令人信服的时间联系，这表明撞击不是喷发的主要驱动力。随着众多竞争性灭绝场景的出现，以及一些所谓的环境压力可能再次推动大规模灭绝的认识，我们探索实验生物学如何为我们对古代灭绝和未来危机的理解提供信息。(C)2016作者由爱思唯尔公司出版
The temporal link between large igneous province (LIP) eruptions and at least half of the major extinctions of the Phanerozoic implies that large scale volcanism is the main driver of mass extinction. Here we review almost twenty biotic crises between the early Cambrian and end Cretaceous and explore potential causal mechanisms. Most extinctions are associated with global warming and proximal killers such as marine anoxia (including the Early/Middle Cambrian, the Late Ordovician, the intra-Silurian, intra-Devonian, end-Permian, and Early Jurassic crises). Many, but not all of these are accompanied by large negative carbon isotope excursions, supporting a volcanogenic origin. Most post-Silurian biocrises affected both terrestrial and marine biospheres, suggesting that atmospheric processes were crucial in driving global extinctions. Volcanogenic-atmospheric kill mechanisms include ocean acidification, toxic metal poisoning, acid rain, and ozone damage and consequent increased UV-B radiation, volcanic darkness, cooling and photosynthetic shutdown, each of which has been implicated in numerous events. Intriguingly, some of the most voluminous LIPs such as the oceanic plateaus of the Cretaceous were emplaced with minimal faunal losses and so volume of magma is not the only factor governing LIP lethality. The missing link might be continental configuration because the best examples of the LIP/extinction relationship occurred during the time of Pangaea. Many of the proximal kill mechanisms in LIP/extinction scenarios are also potential effects of bolide impact, including cooling, warming, acidification and ozone destruction. However, the absence of convincing temporal links between impacts and extinctions other than the Chicxulub-Cretaceous example, suggests that impacts are not the main driver of extinctions. With numerous competing extinction scenarios, and the realisation that some of the purported environmental stresses may once again be driving mass extinction, we explore how experimental biology might inform our understanding of ancient extinctions as well as future crises. (C) 2016 The Authors. Published by Elsevier B.V.