The Pleistocene species pump past its prime : evidence from European butterfly sister species
Abstract
The Pleistocene glacial cycles had a profound impact on the ranges and genetic make-up of organisms. Whilst it is clear that the contact zones that have been described for many sister taxa are secondary and have formed during the last interglacial, it is unclear when the taxa involved began to diverge. Previous estimates based on small numbers of loci are unreliable given the stochasticity of genetic drift and the contrasting effects of incomplete lineage sorting and gene flow on gene divergence. Here we use genome-wide transcriptome data to estimate divergence for 18 sister species pairs of European butterflies showing either sympatric or contact zone distributions. We find that in most cases species divergence predates the mid-Pleistocene transition or even the entire Pleistocene period. We also show that although post divergence gene flow is restricted to contact zone pairs, they are not systematically younger than sympatric pairs. This suggests that contact zones are not limited to the initial stages of the speciation process, but can involve notably old taxa. Finally, we show that mitochondrial and nuclear divergence are only weakly correlated and mitochondrial divergence is higher for contact-zone pairs.
Citation
Ebdon , S , Laetsch , D R , Dapporto , L , Hayward , A , Ritchie , M G , Dincă , V , Vila , R & Lohse , K 2021 , ' The Pleistocene species pump past its prime : evidence from European butterfly sister species ' , Molecular Ecology , vol. Early View . https://doi.org/10.1111/mec.15981
Publication
Molecular Ecology
Status
Peer reviewed
ISSN
0962-1083Type
Journal article
Rights
Copyright © 2021 The Authors. Molecular Ecology published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Description
Funding: This work was supported by an ERC starting grant (ModelGenomLand). SE is supported by an EastBio studentship from the British Biological Sciences Research Council (BBSRC). KL is supported by a fellowship from the Natural Environment Research Council (NERC, NE/L011522/1). VD is supported by the Academy of Finland (Academy Research Fellow, decision no. 328895). RV acknowledges support from project PID2019-107078GB-I00 (AEI, Spain/ERDF, EU). LD acknowledges support from project ”Ricerca e conservazione sugli Impollinatori dell’Arcipelago Toscano e divulgazione sui Lepidotteri del parco”. AH is supported by a Biotechnology and Biological Sciences Research Council (BBSRC) David Phillips Fellowship (BB/N020146/1).Collections
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