Lessons from the past: Biotic recoveries from mass extinctions

Abstract

Although mass extinctions probably account for the disappearance of less than 5% of all extinct species, the evolutionary opportunities they have created have had a disproportionate effect on the history of life. Theoretical considerations and simulations have suggested that the empty niches created by a mass extinction should refill rapidly after extinction ameliorates. Under logistic models, this biotic rebound should be exponential, slowing as the environmental carrying capacity is approached. Empirical studies reveal a more complex dynamic, including positive feedback and an exponential growth phase during recoveries. Far from a model of refilling ecospace, mass extinctions appear to cause a collapse of ecospace, which must be rebuilt during recovery. Other generalities include the absence of a clear correlation between the magnitude of extinction and the pace of recovery or the resulting ecological and evolutionary disruption the presence of a survival interval, with few originations, immediately after an extinction and preceding the recovery phase, and the presence of many lineages that persist through an extinction event only to disappear during the subsequent recovery. Several recoveries include numerous missing lineages, groups that are found before the extinction, then latter in the recovery, but are missing during the initial survival-recovery phase. The limited biogeographic studies of recoveries suggest considerable variability between regions.H owever much one may mourn the passing of trilobites, conodonts, ammonoids, richtofenid brachiopods, and even dinosaurs, there is no denying the profound evolutionary impetus mass extinctions have provided to the history of life. Mass extinctions create new evolutionary opportunities and redirect the course of evolution. During the past two decades, paleontologists have focused great effort on the patterns, rates, and causes of various mass extinctions. Our understanding of these events has improved greatly, but postextinction rebounds have received far less attention. This lack of attention is unfortunate, for the available detailed empirical studies of recoveries have revealed great complexity to postextinction rebounds, raising questions about the applicability of many models of evolutionary dynamics. Analysis of these extensive biotic disturbances provides detailed information about how ecosystems respond to perturbations and the processes underlying diversification, and insights into what we might plausibly expect from our current biodiversity crisis. In this paper, I will place recovery studies within the context of models of biodiversity dynamics, review the results of both modeling work and empirical studies of specific postextinction recoveries, consider the general patterns that can be derived from a comparative study of recoveries, and close with a discussion of the evolutionary significance of biotic recoveries. Recoveries and Biodiversity DynamicsPaleontological discussions of postextinction recoveries have been heavily influenced by models of ev...

Phylogenetic trees and the future of mammalian biodiversity

“…The evolutionary future of life on Earth is therefore unlikely to be in serious jeopardy. Second, anthropogenic environmental change and extinctions are occurring on the order of tens to hundreds of years, but times to speciation are frequently estimated in thousands to millions of years (87), and recovery times after previous mass extinction events were perhaps 5-10 million years (12). These time scales are too great for practical management.…”

Amelioration of marine environments at the Smithian–Spathian boundary, Early Triassic

“…During the Early to Middle Triassic, the Ziyun area was located on the southern margin of the Yangtze Platform, to the north of the Nanpanjiang Basin . The paleogeographic configuration of the Ziyun area changed from a platform-margin reef system in the latest Permian to a platform-ramp environment in the Early Triassic (Feng et al, 1997). In this area of the Nanpanjiang Basin in southern Guizhou Province, the Upper Permian successions usually comprise bioclastic rocks, which are collectively assigned to the Wujiaping Formation.…”

“…The recovery of marine invertebrate faunas and ecosystems after the ∼ 252 Ma end-Permian mass extinction appears to have been the most protracted following any Phanerozoic biocrisis (Erwin, 2001;. As with the mass extinction event, many aspects of the Early Triassic recovery remain uncertain, including its timing, pattern, and causes.…”

Long-term legacy of massive carbon input to the Earth system: Anthropocene versus Eocene

“…For example, biotic diversity after major extinction events throughout the Phanerozoic required of the order of 5 Myr to rebound [16,[79][80][81][82] 65 Ma, which have traditionally been labelled the 'big five' extinctions. However, more recent studies point out that perhaps only three events qualify as true global mass extinctions, among them the End-Permian and End-Cretaceous [16,81].…”