Cargando…

Land-Bridge Calibration of Molecular Clocks and the Post-Glacial Colonization of Scandinavia by the Eurasian Field Vole Microtus agrestis

Phylogeography interprets molecular genetic variation in a spatial and temporal context. Molecular clocks are frequently used to calibrate phylogeographic analyses, however there is mounting evidence that molecular rates decay over the relevant timescales. It is therefore essential that an appropria...

Descripción completa

Detalles Bibliográficos
Autores principales: Herman, Jeremy S., McDevitt, Allan D., Kawałko, Agata, Jaarola, Maarit, Wójcik, Jan M., Searle, Jeremy B.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4128820/
https://www.ncbi.nlm.nih.gov/pubmed/25111840
http://dx.doi.org/10.1371/journal.pone.0103949
_version_ 1782330180050616320
author Herman, Jeremy S.
McDevitt, Allan D.
Kawałko, Agata
Jaarola, Maarit
Wójcik, Jan M.
Searle, Jeremy B.
author_facet Herman, Jeremy S.
McDevitt, Allan D.
Kawałko, Agata
Jaarola, Maarit
Wójcik, Jan M.
Searle, Jeremy B.
author_sort Herman, Jeremy S.
collection PubMed
description Phylogeography interprets molecular genetic variation in a spatial and temporal context. Molecular clocks are frequently used to calibrate phylogeographic analyses, however there is mounting evidence that molecular rates decay over the relevant timescales. It is therefore essential that an appropriate rate is determined, consistent with the temporal scale of the specific analysis. This can be achieved by using temporally spaced data such as ancient DNA or by relating the divergence of lineages directly to contemporaneous external events of known time. Here we calibrate a Eurasian field vole (Microtus agrestis) mitochondrial genealogy from the well-established series of post-glacial geophysical changes that led to the formation of the Baltic Sea and the separation of the Scandinavian peninsula from the central European mainland. The field vole exhibits the common phylogeographic pattern of Scandinavian colonization from both the north and the south, however the southernmost of the two relevant lineages appears to have originated in situ on the Scandinavian peninsula, or possibly in the adjacent island of Zealand, around the close of the Younger Dryas. The mitochondrial substitution rate and the timescale for the genealogy are closely consistent with those obtained with a previous calibration, based on the separation of the British Isles from mainland Europe. However the result here is arguably more certain, given the level of confidence that can be placed in one of the central assumptions of the calibration, that field voles could not survive the last glaciation of the southern part of the Scandinavian peninsula. Furthermore, the similarity between the molecular clock rate estimated here and those obtained by sampling heterochronous (ancient) DNA (including that of a congeneric species) suggest that there is little disparity between the measured genetic divergence and the population divergence that is implicit in our land-bridge calibration.
format Online
Article
Text
id pubmed-4128820
institution National Center for Biotechnology Information
language English
publishDate 2014
publisher Public Library of Science
record_format MEDLINE/PubMed
spelling pubmed-41288202014-08-12 Land-Bridge Calibration of Molecular Clocks and the Post-Glacial Colonization of Scandinavia by the Eurasian Field Vole Microtus agrestis Herman, Jeremy S. McDevitt, Allan D. Kawałko, Agata Jaarola, Maarit Wójcik, Jan M. Searle, Jeremy B. PLoS One Research Article Phylogeography interprets molecular genetic variation in a spatial and temporal context. Molecular clocks are frequently used to calibrate phylogeographic analyses, however there is mounting evidence that molecular rates decay over the relevant timescales. It is therefore essential that an appropriate rate is determined, consistent with the temporal scale of the specific analysis. This can be achieved by using temporally spaced data such as ancient DNA or by relating the divergence of lineages directly to contemporaneous external events of known time. Here we calibrate a Eurasian field vole (Microtus agrestis) mitochondrial genealogy from the well-established series of post-glacial geophysical changes that led to the formation of the Baltic Sea and the separation of the Scandinavian peninsula from the central European mainland. The field vole exhibits the common phylogeographic pattern of Scandinavian colonization from both the north and the south, however the southernmost of the two relevant lineages appears to have originated in situ on the Scandinavian peninsula, or possibly in the adjacent island of Zealand, around the close of the Younger Dryas. The mitochondrial substitution rate and the timescale for the genealogy are closely consistent with those obtained with a previous calibration, based on the separation of the British Isles from mainland Europe. However the result here is arguably more certain, given the level of confidence that can be placed in one of the central assumptions of the calibration, that field voles could not survive the last glaciation of the southern part of the Scandinavian peninsula. Furthermore, the similarity between the molecular clock rate estimated here and those obtained by sampling heterochronous (ancient) DNA (including that of a congeneric species) suggest that there is little disparity between the measured genetic divergence and the population divergence that is implicit in our land-bridge calibration. Public Library of Science 2014-08-11 /pmc/articles/PMC4128820/ /pubmed/25111840 http://dx.doi.org/10.1371/journal.pone.0103949 Text en © 2014 Herman et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Herman, Jeremy S.
McDevitt, Allan D.
Kawałko, Agata
Jaarola, Maarit
Wójcik, Jan M.
Searle, Jeremy B.
Land-Bridge Calibration of Molecular Clocks and the Post-Glacial Colonization of Scandinavia by the Eurasian Field Vole Microtus agrestis
title Land-Bridge Calibration of Molecular Clocks and the Post-Glacial Colonization of Scandinavia by the Eurasian Field Vole Microtus agrestis
title_full Land-Bridge Calibration of Molecular Clocks and the Post-Glacial Colonization of Scandinavia by the Eurasian Field Vole Microtus agrestis
title_fullStr Land-Bridge Calibration of Molecular Clocks and the Post-Glacial Colonization of Scandinavia by the Eurasian Field Vole Microtus agrestis
title_full_unstemmed Land-Bridge Calibration of Molecular Clocks and the Post-Glacial Colonization of Scandinavia by the Eurasian Field Vole Microtus agrestis
title_short Land-Bridge Calibration of Molecular Clocks and the Post-Glacial Colonization of Scandinavia by the Eurasian Field Vole Microtus agrestis
title_sort land-bridge calibration of molecular clocks and the post-glacial colonization of scandinavia by the eurasian field vole microtus agrestis
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4128820/
https://www.ncbi.nlm.nih.gov/pubmed/25111840
http://dx.doi.org/10.1371/journal.pone.0103949
work_keys_str_mv AT hermanjeremys landbridgecalibrationofmolecularclocksandthepostglacialcolonizationofscandinaviabytheeurasianfieldvolemicrotusagrestis
AT mcdevittalland landbridgecalibrationofmolecularclocksandthepostglacialcolonizationofscandinaviabytheeurasianfieldvolemicrotusagrestis
AT kawałkoagata landbridgecalibrationofmolecularclocksandthepostglacialcolonizationofscandinaviabytheeurasianfieldvolemicrotusagrestis
AT jaarolamaarit landbridgecalibrationofmolecularclocksandthepostglacialcolonizationofscandinaviabytheeurasianfieldvolemicrotusagrestis
AT wojcikjanm landbridgecalibrationofmolecularclocksandthepostglacialcolonizationofscandinaviabytheeurasianfieldvolemicrotusagrestis
AT searlejeremyb landbridgecalibrationofmolecularclocksandthepostglacialcolonizationofscandinaviabytheeurasianfieldvolemicrotusagrestis