The influence of body size and net diversification rate on molecular evolution during the radiation of animal phyla

Date

2007-06-26

Authors

Fontanillas, Eric
Welch, John J.
Thomas, Jessica
Bromham, Lindell

Journal Title

Journal ISSN

Volume Title

Publisher

BioMed Central

Abstract

BACKGROUND: Molecular clock dates, which place the origin of animal phyla deep in the Precambrian, have been used to reject the hypothesis of a rapid evolutionary radiation of animal phyla supported by the fossil record. One possible explanation of the discrepancy is the potential for fast substitution rates early in the metazoan radiation. However, concerted rate variation, occurring simultaneously in multiple lineages, cannot be detected by "clock tests", and so another way to explore such variation is to look for correlated changes between rates and other biological factors. Here we investigate two possible causes of fast early rates: change in average body size or diversification rate of deep metazoan lineages. RESULTS: For nine genes for phylogenetically independent comparisons between 50 metazoan phyla, orders, and classes, we find a significant correlation between average body size and rate of molecular evolution of mitochondrial genes. The data also indicate that diversification rate may have a positive effect on rates of mitochondrial molecular evolution. CONCLUSION: If average body sizes were significantly smaller in the early history of the Metazoa, and if rates of diversification were much higher, then it is possible that mitochondrial genes have undergone a slow-down in evolutionary rate, which could affect date estimates made from these genes.

Description

Keywords

Keywords: article; body size; controlled study; correlation coefficient; metazoon; mitochondrial gene; molecular evolution; nonhuman; phylogeny; phylum; animal; biological model; classification; comparative study; evolution; genetics; histology; mutation; sequence

Citation

BMC Evolutionary Biology 7.95 (2007)

Source

BMC Evolutionary Biology

Type

Journal article

Book Title

Entity type

Access Statement

License Rights

DOI

10.1186/1471-2148-7-95

Restricted until