Reduced strength and increased variability of extinction selectivity during mass extinctions

Abstract

Two of the traits most often observed to correlate with extinction risk in marine animals are geographical range and body size. However, the relative effects of these two traits on extinction risk have not been investigated systematically for either background times or during mass extinctions. To close this knowledge gap, we measure and compare extinction selectivity of geographical range and body size of genera within five classes of benthic marine animals across the Phanerozoic using capture–mark–recapture models. During background intervals, narrow geographical range is strongly associated with greater extinction probability, whereas smaller body size is more weakly associated with greater extinction probability. During mass extinctions, the association between geographical range and extinction probability is reduced in every class and fully eliminated in some, whereas the association between body size and extinction probability varies in strength and direction across classes. While geographical range is universally the stronger predictor of survival during background intervals, variation among classes during mass extinction suggests a fundamental shift in extinction processes during these global catastrophes.

Trait-mediated speciation and human-driven extinctions in proboscideans revealed by unsupervised Bayesian neural networks

“…However, as productivity and ecosystem functioning recover, niches related to larger body sizes could have greater diversification potential once smaller-sized guilds become saturated (13,46). While some of the models allow for a joint analysis of combined multiple factors (e.g., multiple traits or time variables), they typically assume that their effects are additive, independent, and constrained by monotonic (often linear) functions (47)(48)(49)(50)(51). Thus, any potential nonlinear effects and the shifting interplay between species attributes and paleoenvironmental changes in regulating speciation and extinction rates have proven elusive to quantify.…”