Widespread phenotypic and genetic divergence along altitudinal gradients in animals
Publisher DOI
Abstract
Altitudinal gradients offer valuable study systems to investigate how adap-
tive genetic diversity is distributed within and between natural populations
and which factors promote or prevent adaptive differentiation. The environ-
mental clines along altitudinal gradients tend to be steep relative to the
dispersal distance of many organisms, providing an opportunity to study the
joint effects of divergent natural selection and gene flow. Temperature is
one variable showing consistent altitudinal changes, and altitudinal gradi-
ents can therefore provide spatial surrogates for some of the changes antici-
pated under climate change. Here, we investigate the extent and patterns of
adaptive divergence in animal populations along altitudinal gradients by sur-
veying the literature for (i) studies on phenotypic variation assessed under
common garden or reciprocal transplant designs and (ii) studies looking for
signatures of divergent selection at the molecular level. Phenotypic data
show that significant between-population differences are common and taxo-
nomically widespread, involving traits such as mass, wing size, tolerance to
thermal extremes and melanization. Several lines of evidence suggest that
some of the observed differences are adaptively relevant, but rigorous tests
of local adaptation or the link between specific phenotypes and fitness are
sorely lacking. Evidence for a role of altitudinal adaptation also exists for a
number of candidate genes, most prominently haemoglobin, and for anony-
mous molecular markers. Novel genomic approaches may provide valuable
tools for studying adaptive diversity, also in species that are not amenable to
experimentation.
tive genetic diversity is distributed within and between natural populations
and which factors promote or prevent adaptive differentiation. The environ-
mental clines along altitudinal gradients tend to be steep relative to the
dispersal distance of many organisms, providing an opportunity to study the
joint effects of divergent natural selection and gene flow. Temperature is
one variable showing consistent altitudinal changes, and altitudinal gradi-
ents can therefore provide spatial surrogates for some of the changes antici-
pated under climate change. Here, we investigate the extent and patterns of
adaptive divergence in animal populations along altitudinal gradients by sur-
veying the literature for (i) studies on phenotypic variation assessed under
common garden or reciprocal transplant designs and (ii) studies looking for
signatures of divergent selection at the molecular level. Phenotypic data
show that significant between-population differences are common and taxo-
nomically widespread, involving traits such as mass, wing size, tolerance to
thermal extremes and melanization. Several lines of evidence suggest that
some of the observed differences are adaptively relevant, but rigorous tests
of local adaptation or the link between specific phenotypes and fitness are
sorely lacking. Evidence for a role of altitudinal adaptation also exists for a
number of candidate genes, most prominently haemoglobin, and for anony-
mous molecular markers. Novel genomic approaches may provide valuable
tools for studying adaptive diversity, also in species that are not amenable to
experimentation.
Date Issued
2013
Publication Type
Article
Subject(s)
Language(s)
en
Author(s)
Alexander, J. M. | |
Holderegger, R. | |
Edwards, P. J. |
Additional Credits
Journal
Journal of Evolutionary Biology
Publisher
Wiley
ISSN
1010-061X
Access(Rights)
restricted