dorsal/arxiv
View SchemaMetabolic Rate Calibrates the Molecular Clock: Reconciling Molecular and Fossil Estimates of Evolutionary Divergence
| Authors | James F. Gillooly, Andrew P. Allen, Geoffrey B. West, James H. Brown |
|---|---|
| Categories | |
| ArXiv ID | q-bio/0404027 |
| URL | https://arxiv.org/abs/q-bio/0404027 |
Abstract
Observations that rates of molecular evolution vary widely within and among lineages have cast doubts upon the existence of a single molecular clock. Differences in the timing of evolutionary events estimated from genetic and fossil evidence have raised further questions about the existence of molecular clocks and their use. Here we present a model of nucleotide substitution that combines new theory on metabolic rate with the now classic neutral theory of molecular evolution. The model quantitatively predicts rate heterogeneity, and reconciles differences in molecular- and fossil-estimated dates of evolutionary events. Model predictions are supported by extensive data from mitochondrial and nuclear genomes. By accounting for the effects of body size and temperature on metabolic rate, a single molecular clock explains heterogeneity in rates of nucleotide substitution in different genes, taxa, and thermal environments. This model suggests that there is indeed a general molecular clock, as originally proposed by Zuckerkandl and Pauling, but that it ticks at a constant substitution rate per unit mass-specific metabolic energy rather than per unit time. More generally, the model suggests that body size and temperature combine to control the overall rate of evolution through their effects on metabolism.
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"abstract": "Observations that rates of molecular evolution vary widely within and among\nlineages have cast doubts upon the existence of a single molecular clock.\nDifferences in the timing of evolutionary events estimated from genetic and\nfossil evidence have raised further questions about the existence of molecular\nclocks and their use. Here we present a model of nucleotide substitution that\ncombines new theory on metabolic rate with the now classic neutral theory of\nmolecular evolution. The model quantitatively predicts rate heterogeneity, and\nreconciles differences in molecular- and fossil-estimated dates of evolutionary\nevents. Model predictions are supported by extensive data from mitochondrial\nand nuclear genomes. By accounting for the effects of body size and temperature\non metabolic rate, a single molecular clock explains heterogeneity in rates of\nnucleotide substitution in different genes, taxa, and thermal environments.\nThis model suggests that there is indeed a general molecular clock, as\noriginally proposed by Zuckerkandl and Pauling, but that it ticks at a constant\nsubstitution rate per unit mass-specific metabolic energy rather than per unit\ntime. More generally, the model suggests that body size and temperature combine\nto control the overall rate of evolution through their effects on metabolism.",
"arxiv_id": "q-bio/0404027",
"authors": [
"James F. Gillooly",
"Andrew P. Allen",
"Geoffrey B. West",
"James H. Brown"
],
"categories": [
"q-bio.PE",
"q-bio.GN"
],
"title": "Metabolic Rate Calibrates the Molecular Clock: Reconciling Molecular and Fossil Estimates of Evolutionary Divergence",
"url": "https://arxiv.org/abs/q-bio/0404027"
},
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