A. Siepielsk, K. Gotanda, M. Morrissey, S. Diamond, J. DiBattista, S. Carlson
Ecology Letters, 16, 1382-1392, (2013)
Adaptation, Environmental variation, Evolution, Local adaptation, Natural selection, Selection mosaic, Sexualselection, Spatial variation.
Local adaptation, adaptive population divergence and speciation are
often expected to result from populations evolving in response to
spatial variation in selection. Yet, we lack a comprehensive
understanding of the major features that characterise the spatial
patterns of selection, namely the extent of variation among populations
in the strength and direction of selection. Here, we analyse a data set
of spatially replicated studies of directional phenotypic selection from
natural populations. The data set includes 60 studies, consisting of
3937 estimates of selection across an average of five populations. We
performed meta-analyses to explore features characterising spatial
variation in directional selection. We found that selection tends to
vary mainly in strength and less in direction among populations.
Although differences in the direction of selection occur among
populations they do so where selection is often weakest, which may limit
the potential for ongoing adaptive population divergence. Overall, we
also found that spatial variation in selection appears comparable to
temporal (annual) variation in selection within populations; however,
several deficiencies in available data currently complicate this
comparison. We discuss future research needs to further advance our
understanding of spatial variation in selection.