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Vicariance divergence and gene flow among islet populations of an endemic lizard.

Runemark, Anna LU ; Hey, Jody; Hansson, Bengt LU and Svensson, Erik LU (2012) In Molecular Ecology 21(1). p.117-129
Abstract
Allopatry and allopatric speciation can arise through two different mechanisms: vicariance or colonization through dispersal. Distinguishing between these different allopatric mechanisms is difficult and one of the major challenges in biogeographical research. Here, we address whether allopatric isolation in an endemic island lizard is the result of vicariance or dispersal. We estimated the amount and direction of gene flow during the divergence of isolated islet populations and subspecies of the endemic Skyros wall lizard Podarcis gaigeae, a phenotypically variable species that inhabits a major island and small islets in the Greek archipelago. We applied isolation-with-migration models to estimate population divergence times, population... (More)
Allopatry and allopatric speciation can arise through two different mechanisms: vicariance or colonization through dispersal. Distinguishing between these different allopatric mechanisms is difficult and one of the major challenges in biogeographical research. Here, we address whether allopatric isolation in an endemic island lizard is the result of vicariance or dispersal. We estimated the amount and direction of gene flow during the divergence of isolated islet populations and subspecies of the endemic Skyros wall lizard Podarcis gaigeae, a phenotypically variable species that inhabits a major island and small islets in the Greek archipelago. We applied isolation-with-migration models to estimate population divergence times, population sizes and gene flow between islet-mainland population pairs. Divergence times were significantly correlated with independently estimated geological divergence times. This correlation strongly supports a vicariance scenario where islet populations have sequentially become isolated from the major island. We did not find evidence for significant gene flow within P. g. gaigeae. However, gene-flow estimates from the islet to the mainland populations were positively affected by islet area and negatively by distance between the islet and mainland. We also found evidence for gene flow from one subspecies (P. g. weigandi) into another (P. g. gaigeae), but not in the other direction. Ongoing gene flow between the subspecies suggests that even in this geographically allopatric scenario with the sea posing a strong barrier to dispersal, divergence with some gene flow is still feasible. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
biogeography, dispersal, evolutionary divergence, gene flow, IMa2, vicariance
in
Molecular Ecology
volume
21
issue
1
pages
117 - 129
publisher
Wiley-Blackwell
external identifiers
  • wos:000298582700010
  • pmid:22129244
  • scopus:84155162968
ISSN
0962-1083
DOI
10.1111/j.1365-294X.2011.05377.x
language
English
LU publication?
yes
id
c19ad547-0d29-47da-b5d6-13667fd055d9 (old id 2274748)
date added to LUP
2012-02-07 16:58:18
date last changed
2017-11-05 03:24:26
@article{c19ad547-0d29-47da-b5d6-13667fd055d9,
  abstract     = {Allopatry and allopatric speciation can arise through two different mechanisms: vicariance or colonization through dispersal. Distinguishing between these different allopatric mechanisms is difficult and one of the major challenges in biogeographical research. Here, we address whether allopatric isolation in an endemic island lizard is the result of vicariance or dispersal. We estimated the amount and direction of gene flow during the divergence of isolated islet populations and subspecies of the endemic Skyros wall lizard Podarcis gaigeae, a phenotypically variable species that inhabits a major island and small islets in the Greek archipelago. We applied isolation-with-migration models to estimate population divergence times, population sizes and gene flow between islet-mainland population pairs. Divergence times were significantly correlated with independently estimated geological divergence times. This correlation strongly supports a vicariance scenario where islet populations have sequentially become isolated from the major island. We did not find evidence for significant gene flow within P. g. gaigeae. However, gene-flow estimates from the islet to the mainland populations were positively affected by islet area and negatively by distance between the islet and mainland. We also found evidence for gene flow from one subspecies (P. g. weigandi) into another (P. g. gaigeae), but not in the other direction. Ongoing gene flow between the subspecies suggests that even in this geographically allopatric scenario with the sea posing a strong barrier to dispersal, divergence with some gene flow is still feasible.},
  author       = {Runemark, Anna and Hey, Jody and Hansson, Bengt and Svensson, Erik},
  issn         = {0962-1083},
  keyword      = {biogeography,dispersal,evolutionary divergence,gene flow,IMa2,vicariance},
  language     = {eng},
  number       = {1},
  pages        = {117--129},
  publisher    = {Wiley-Blackwell},
  series       = {Molecular Ecology},
  title        = {Vicariance divergence and gene flow among islet populations of an endemic lizard.},
  url          = {http://dx.doi.org/10.1111/j.1365-294X.2011.05377.x},
  volume       = {21},
  year         = {2012},
}