geographic structure
Knowles LL 2009 Statistical phylogeography. Annu Rev Ecol Evol Syst 40:593-612.
- the spread of phylogeography's integrative tradition to analyses of non-neutral variation is becoming increasingly evident
- a virtually untested, yet critically important determinant of whether environmental change will out-pace the potential for adaptive evolution is whether selection acts on new mutation versus standing genetic variation
- where not only the spatial distribution of phenotypes and selected loci but also the distributional patterns of neutral variation are compared, adaptive divergence arising from pre-existing variation or via new mutation might be distinguished
- pioneering work on the source of adaptive changes associated with the transition from a marine to freshwater habitat in the three-spine stickleback (Colosimo et al. 2005) reinforces the virtues of the integrative tradition upon which phylogeographic study drives much of its power
- sequencing of individuals from different populations ... indicated a common origin for the allele conferring the adaptive phenotype of low-plate armor in stickleback fish from freshwater habitats
- members of this clade of low-plate alleles are present at low frequencies in marine fish
- standing genetic variation (that is, pre-existing ancestral variation) may have been the source for rapid, parallel adaptive phenotypic change in these freshwater sticklebacks, as opposed to new mutations
- parallel evolution has occurred by repeated selection or pre-existing Eda alleles
- the unprecedented demographic details now provided by statistical phylogeographic study highlight the impact that the shift toward a model-based multilocus perspective has had on historical inference
