There is no universal molecular clock for invertebrates, but rate variation does not scale with body size

Thomas, Jessica A., Welch, John J., Woolfit, Megan and Bromham, Lindell (2006) There is no universal molecular clock for invertebrates, but rate variation does not scale with body size. Proceedings of the National Academy of Sciences of the United States of America., 103 19: 7366-7371. doi:10.1073/pnas.0510251103


Author Thomas, Jessica A.
Welch, John J.
Woolfit, Megan
Bromham, Lindell
Title There is no universal molecular clock for invertebrates, but rate variation does not scale with body size
Journal name Proceedings of the National Academy of Sciences of the United States of America.   Check publisher's open access policy
ISSN 0027-8424
1091-6490
Publication date 2006-05-09
Sub-type Article (original research)
DOI 10.1073/pnas.0510251103
Open Access Status Not Open Access
Volume 103
Issue 19
Start page 7366
End page 7371
Total pages 6
Place of publication Washington, D. C.
Publisher National Academy of Sciences of the U.S.
Language eng
Subject 060409 Molecular Evolution
06 Biological Sciences
Abstract The existence of a universal molecular clock has been called into question by observations that substitution rates vary widely between lineages. However, increasing empirical evidence for the systematic effects of different life history traits on the rate of molecular evolution has raised hopes that rate variation may be predictable, potentially allowing the “correction” of the molecular clock. One such example is the body size trend observed in vertebrates; smaller species tend to have faster rates of molecular evolution. This effect has led to the proposal of general predictive models correcting for rate heterogeneity and has also been invoked to explain discrepancies between molecular and paleontological dates for explosive radiations in the fossil record. Yet, there have been no tests of an effect in any nonvertebrate taxa. In this study, we have tested the generality of the body size effect by surveying a wide range of invertebrate metazoan lineages. DNA sequences and body size data were collected from the literature for 330 species across five phyla. Phylogenetic comparative methods were used to investigate a relationship between average body size and substitution rate at both interspecies and interfamily comparison levels. We demonstrate significant rate variation in all phyla and most genes examined, implying a strict molecular clock cannot be assumed for the Metazoa. Furthermore, we find no evidence of any influence of body size on invertebrate substitution rates. We conclude that the vertebrate body size effect is a special case, which cannot be simply extrapolated to the rest of the animal kingdom.
Keyword comparative method
generation time
metabolic rate
Metazoa
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
School of Biological Sciences Publications
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 72 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 71 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Fri, 19 Dec 2008, 16:32:47 EST by Diana Guillemin on behalf of School of Biological Sciences