Evolutionary Model of Species Body Mass Diversification

TL;DR

This paper introduces a quantitative evolutionary model for species body mass diversification, capturing how mass evolves through speciation, diffusion, and extinction, aligning well with empirical data on mammals.

Contribution

It presents a novel convection-diffusion-reaction model for body mass evolution, incorporating extinction probability increasing with mass, validated against fossil and recent data.

Findings

Model accurately reproduces current mammal body mass distribution.

Time-dependent predictions match extinct mammal data from 95-50 million years ago.

Steady-state results align with empirical observations.

Abstract

We present a quantitative model for the biological evolution of species body masses within large groups of related species, e.g., terrestrial mammals, in which body mass M evolves according to branching (speciation), multiplicative diffusion, and an extinction probability that increases logarithmically with mass. We describe this evolution in terms of a convection-diffusion-reaction equation for ln M. The steady-state behavior is in good agreement with empirical data on recent terrestrial mammals, and the time-dependent behavior also agrees with data on extinct mammal species between 95 - 50 Myr ago.