Diversity associations as stochastic variables

Abstract

Diversity data from stochastic phylogenies and from uniformly spaced Gaussian curves were subjected to Q-mode factor analysis in order to determine whether a few factors would account for a large percentage of the original variance. In both analyses, a small number of factors show systematic variations in time and account for more than 90% of original data variance. To further study the question of evolutionary pulsations, turnover rates were calculated between successive samples. These turnover rates indicate that stochastic phylogenies have pulses similar to those recorded in the fossil record. Large scale environmental changes are not required to explain such pulses. Therefore the observed existence in the real world of biologic diversity associations and evolutionary pulsations can as equally well be accounted for in a stochastic world (in which each species is an independent variable) as in a deterministic world. This supports the notion that there may be stochastic laws in paleontology akin to the gas laws of chemistry.