When organisms adapt to spatially heterogeneous environments, selection may
drive divergence at multiple genes. If populations under divergent selection
also exchange migrants, we expect genetic differentiation to be high at
selected loci, relative to the baseline caused by migration and genetic drift.
Indeed, empirical studies have found peaks of putatively adaptive
differentiation. These are highly variable in length, some of them extending
over several hundreds of thousands of base pairs. How can such `islands of
differentiation' be explained? Physical linkage produces elevated levels of
differentiation at loci close to genes under selection. However, whether this
is enough to account for the observed patterns of divergence is not well
understood. Here, we investigate the fate of a locally beneficial mutation that
arises in linkage to an existing migration-selection polymorphism and derive
two important quantities: the probability that the mutation becomes
established, and the expected time to its extinction. We find that intermediate
levels of recombinations are sometimes favourable, and that physical linkage
can lead to strongly elevated invasion probabilities and extinction times. We
provide a rule of thumb for when this is the case. Moreover, we quantify the
long-term effect of polygenic local adaptation on linked neutral variation.
%0 Generic
%1 aeschbacher2013effect
%A Aeschbacher, Simon
%A Bürger, Reinhard
%D 2013
%K branching_process_approximation diffusion_approximation linkage multilocus mutation_selection_balance probability_of_survival
%T The effect of linkage on establishment and survival of locally
beneficial mutations
%U http://arxiv.org/abs/1311.6326
%X When organisms adapt to spatially heterogeneous environments, selection may
drive divergence at multiple genes. If populations under divergent selection
also exchange migrants, we expect genetic differentiation to be high at
selected loci, relative to the baseline caused by migration and genetic drift.
Indeed, empirical studies have found peaks of putatively adaptive
differentiation. These are highly variable in length, some of them extending
over several hundreds of thousands of base pairs. How can such `islands of
differentiation' be explained? Physical linkage produces elevated levels of
differentiation at loci close to genes under selection. However, whether this
is enough to account for the observed patterns of divergence is not well
understood. Here, we investigate the fate of a locally beneficial mutation that
arises in linkage to an existing migration-selection polymorphism and derive
two important quantities: the probability that the mutation becomes
established, and the expected time to its extinction. We find that intermediate
levels of recombinations are sometimes favourable, and that physical linkage
can lead to strongly elevated invasion probabilities and extinction times. We
provide a rule of thumb for when this is the case. Moreover, we quantify the
long-term effect of polygenic local adaptation on linked neutral variation.
@misc{aeschbacher2013effect,
abstract = {When organisms adapt to spatially heterogeneous environments, selection may
drive divergence at multiple genes. If populations under divergent selection
also exchange migrants, we expect genetic differentiation to be high at
selected loci, relative to the baseline caused by migration and genetic drift.
Indeed, empirical studies have found peaks of putatively adaptive
differentiation. These are highly variable in length, some of them extending
over several hundreds of thousands of base pairs. How can such `islands of
differentiation' be explained? Physical linkage produces elevated levels of
differentiation at loci close to genes under selection. However, whether this
is enough to account for the observed patterns of divergence is not well
understood. Here, we investigate the fate of a locally beneficial mutation that
arises in linkage to an existing migration-selection polymorphism and derive
two important quantities: the probability that the mutation becomes
established, and the expected time to its extinction. We find that intermediate
levels of recombinations are sometimes favourable, and that physical linkage
can lead to strongly elevated invasion probabilities and extinction times. We
provide a rule of thumb for when this is the case. Moreover, we quantify the
long-term effect of polygenic local adaptation on linked neutral variation.},
added-at = {2013-12-04T22:22:05.000+0100},
author = {Aeschbacher, Simon and B\"urger, Reinhard},
biburl = {https://www.bibsonomy.org/bibtex/2f9264152a6f7e1f6e8aad01ab11eb5aa/peter.ralph},
interhash = {a314c0d54a4fd327bc9a325ca80a487c},
intrahash = {f9264152a6f7e1f6e8aad01ab11eb5aa},
keywords = {branching_process_approximation diffusion_approximation linkage multilocus mutation_selection_balance probability_of_survival},
note = {cite arxiv:1311.6326},
timestamp = {2014-01-08T19:14:06.000+0100},
title = {The effect of linkage on establishment and survival of locally
beneficial mutations},
url = {http://arxiv.org/abs/1311.6326},
year = 2013
}