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Genetic ages for Quaternary topographic evolution: A new dating tool
Citation
Craw, D and Burridge, CP and Norris, R and Waters, J, Genetic ages for Quaternary topographic evolution: A new dating tool, Geological Society of America. Bulletin, 36, (1) pp. 19-22. ISSN 0016-7606 (2008) [Refereed Article]
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Copyright Statement
© 2008 The Geological Society of America.
Official URL: http://geology.gsapubs.org/
Abstract
All eukaryote populations accumulate mutations in their mitochondrial DNA (mtDNA)
over time, so reproductively isolated populations become characterized by distinct mtDNA
lineages. In addition, the degree of genetic differentiation among distinct populations can be
used to estimate time elapsed since their isolation. We have identifi ed an informative system for
calibrating the mtDNA "clock" by genetically comparing freshwater galaxiid fi sh populations
isolated in different river drainages. Calibration using a range of Quaternary geological events
in southern New Zealand shows that the mtDNA divergence rate in galaxiid fi shes is between
1% and 2%/100 k.y. up to 250 k.y., with the rate decreasing with increasing age. The estimated
divergence rate slows to around 4%/m.y. for the middle Quaternary, although calibration
is poor. A calibration curve has been fi tted to all data: divergence (%) = −2.2e–9t + 2.5t + 2.2,
where t is isolation age (in m.y.). This molecular clock has potential as a dating tool for glacially
related and active tectonic events that have caused river drainage changes in the late Quater-
nary in the Southern Hemisphere, where galaxiids are widespread. An application of this dating
tool to an example in northern South Island uses three different species of freshwater-limited
fi sh, and all three data sets imply formation of a drainage divide at 320 ± 110 ka,
at about the time of a major glacial advance though the divide (oxygen isotope stage 8).
Item Details
Item Type: | Refereed Article |
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Keywords: | dating, DNA, New Zealand, tectonics, river capture. |
Research Division: | Earth Sciences |
Research Group: | Geology |
Research Field: | Geochronology |
Objective Division: | Expanding Knowledge |
Objective Group: | Expanding knowledge |
Objective Field: | Expanding knowledge in the earth sciences |
UTAS Author: | Burridge, CP (Associate Professor Christopher Burridge) |
ID Code: | 59418 |
Year Published: | 2008 |
Web of Science® Times Cited: | 36 |
Deposited By: | Zoology |
Deposited On: | 2009-12-01 |
Last Modified: | 2010-06-04 |
Downloads: | 2 View Download Statistics |
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