Does functional redundancy determine the ecological severity of a mass extinction event?

Area of Science:

• Paleontology
• Ecology
• Information Theory

Background:

• Mass extinction events exhibit a decoupling between taxonomic loss and ecological impact.
• Previous explanations for this pattern remain widely debated and lack mechanistic clarity.

Purpose of the Study:

• To investigate the roles of biosphere entropy (functional redundancy) and functional selectivity in determining ecological severity during mass extinctions.
• To provide a mechanistic explanation for the observed decoupling of taxonomic and ecological severity.

Main Methods:

• Utilized an information-theoretic framework to analyze extinction patterns.
• Compared the influence of functional redundancy (biosphere entropy) versus functional selectivity on ecological severity.
• Evaluated theoretical simulations against empirical extinction interval data.

Main Results:

• While theoretical models suggest Shannon entropy influences extinction outcomes, empirical variation in entropy does not adequately explain ecological severity.
• The degree of functional selectivity emerged as the primary driver of ecological impact.
• This effect was particularly pronounced when functional redundancy levels were similar across extinction events.

Conclusions:

• Functional selectivity, rather than functional redundancy, is the key factor governing the ecological severity of mass extinctions.
• This research offers a novel mechanistic explanation for the observed decoupling of taxonomic and ecological severity.
• The findings highlight the importance of functional traits in understanding biodiversity loss dynamics.