Search:
Computing and Library Services - delivering an inspiring information environment

Correcting for Purifying Selection: An Improved Human Mitochondrial Molecular Clock

Soares, Pedro, Ermini, Luca, Thomson, Noel, Mormina, Maru, Rito, Teresa, Röhl, Arne, Salas, Antonio, Oppenheimer, Stephen, Macaulay, Vincent and Richards, Martin B. (2009) Correcting for Purifying Selection: An Improved Human Mitochondrial Molecular Clock. The American Journal of Human Genetics, 84 (6). pp. 740-759. ISSN 00029297

Metadata only available from this repository.

Abstract

There is currently no calibration available for the whole human mtDNA genome, incorporating both coding and control regions. Furthermore, as several authors have pointed out recently, linear molecular clocks that incorporate selectable characters are in any case problematic. We here confirm a modest effect of purifying selection on the mtDNA coding region and propose an improved molecular clock for dating human mtDNA, based on a worldwide phylogeny of > 2000 complete mtDNA genomes and calibrating against recent evidence for the divergence time of humans and chimpanzees. We focus on a time-dependent mutation rate based on the entire mtDNA genome and supported by a neutral clock based on synonymous mutations alone. We show that the corrected rate is further corroborated by archaeological dating for the settlement of the Canary Islands and Remote Oceania and also, given certain phylogeographic assumptions, by the timing of the first modern human settlement of Europe and resettlement after the Last Glacial Maximum. The corrected rate yields an age of modern human expansion in the Americas at 15 kya thatunlike the uncorrected clockmatches the archaeological evidence, but continues to indicate an out-of-Africa dispersal at around 5570 kya, 520 ky before any clear archaeological record, suggesting the need for archaeological research efforts focusing on this time window. We also present improved rates for the mtDNA control region, and the first comprehensive estimates of positional mutation rates for human mtDNA, which are essential for defining mutation models in phylogenetic analyses.

Item Type: Article
Subjects: Q Science > Q Science (General)
Q Science > QH Natural history > QH301 Biology
Schools: School of Applied Sciences
Depositing User: Sara Taylor
Date Deposited: 02 Aug 2012 14:56
Last Modified: 02 Aug 2012 14:56
URI: http://eprints.hud.ac.uk/id/eprint/14444

Item control for Repository Staff only:

View Item

University of Huddersfield, Queensgate, Huddersfield, HD1 3DH Copyright and Disclaimer All rights reserved ©