TY - JOUR

T1 - Evaluation of genetic isolation within an island flora reveals unusually widespread local adaptation and supports sympatric speciation

AU - Papadopulos, Alexander S T

AU - Kaye, Maria

AU - Devaux, Céline

AU - Hipperson, Helen

AU - Lighten, Jackie

AU - Dunning, Luke T

AU - Hutton, Ian

AU - Baker, William J

AU - Butlin, Roger K

AU - Savolainen, Vincent

PY - 2014/8/5

Y1 - 2014/8/5

N2 - It is now recognized that speciation can proceed even when divergent natural selection is opposed by gene flow. Understanding the extent to which environmental gradients and geographical distance can limit gene flow within species can shed light on the relative roles of selection and dispersal limitation during the early stages of population divergence and speciation. On the remote Lord Howe Island (Australia), ecological speciation with gene flow is thought to have taken place in several plant genera. The aim of this study was to establish the contributions of isolation by environment (IBE) and isolation by community (IBC) to the genetic structure of 19 plant species, from a number of distantly related families, which have been subjected to similar environmental pressures over comparable time scales. We applied an individual-based, multivariate, model averaging approach to quantify IBE and IBC, while controlling for isolation by distance (IBD). Our analyses demonstrated that all species experienced some degree of ecologically driven isolation, whereas only 12 of 19 species were subjected to IBD. The prevalence of IBE within these plant species indicates that divergent selection in plants frequently produces local adaptation and supports hypotheses that ecological divergence can drive speciation in sympatry.

AB - It is now recognized that speciation can proceed even when divergent natural selection is opposed by gene flow. Understanding the extent to which environmental gradients and geographical distance can limit gene flow within species can shed light on the relative roles of selection and dispersal limitation during the early stages of population divergence and speciation. On the remote Lord Howe Island (Australia), ecological speciation with gene flow is thought to have taken place in several plant genera. The aim of this study was to establish the contributions of isolation by environment (IBE) and isolation by community (IBC) to the genetic structure of 19 plant species, from a number of distantly related families, which have been subjected to similar environmental pressures over comparable time scales. We applied an individual-based, multivariate, model averaging approach to quantify IBE and IBC, while controlling for isolation by distance (IBD). Our analyses demonstrated that all species experienced some degree of ecologically driven isolation, whereas only 12 of 19 species were subjected to IBD. The prevalence of IBE within these plant species indicates that divergent selection in plants frequently produces local adaptation and supports hypotheses that ecological divergence can drive speciation in sympatry.

KW - Adaptation, Biological

KW - Australia

KW - Computer Simulation

KW - Gene Flow

KW - Genetic Speciation

KW - Genetics, Population

KW - Genotype

KW - Geography

KW - Islands

KW - Models, Genetic

KW - Plant Dispersal

KW - Plants

KW - Reproductive Isolation

KW - Species Specificity

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

U2 - 10.1098/rstb.2013.0342

DO - 10.1098/rstb.2013.0342

M3 - Article

C2 - 24958917

VL - 369

SP - 1

EP - 10

JO - Philosophical Transactions of The Royal Society B: Biological Sciences

JF - Philosophical Transactions of The Royal Society B: Biological Sciences

SN - 0962-8436

IS - 1648

ER -