Range expansion in asexual dandelions: selection for general-purpose genotypes?

Phenotypic plasticity and broad ecological tolerance are hypothesized as important traits in the range expansion of asexual species, because individual asexual lineages have to face spatial and temporal environmental variation with limited opportunity for genetic adaptation. The hypothesis that asexual lineages are general-purpose genotypes (GPG) has been previously tested, with mixed results, in species that have both sexual and asexual variants. Such comparisons can be confounded with intra-specific ploidy level differences that are often observed between the two reproductive types. Avoiding the confounding effects of ploidy differences, we test whether northward range expansion selects for a GPG strategy in asexual lineages of the common dandelion (Taraxacum officinale), a species that shows geographic parthenogenesis. We compared the biomass of asexual lineages that were collected along a geographic transect from close to the asexuals’ area of origin (central Europe, where asexuals ...