Evolution of the Sabulina verna group (Caryophyllaceae) in Europe: A deep split, followed by secondary contacts, multiple allopolyploidization and colonization of challenging substrates.

One of the major goals of contemporary evolutionary biology is to elucidate the relative roles of allopatric and ecological differentiation and polyploidy in speciation. In this study, we address the taxonomically intricate Sabulina verna group, which has a disjunct Arctic-alpine postglacial range in Europe and occupies a broad range of ecological niches, including substrates toxic to plants. Using genome-wide ddRAD sequencing combined with morphometric analyses based on extensive sampling of 111 natural populations, we aimed to disentangle internal evolutionary relationships and examine their correspondence with the pronounced edaphic and ploidy diversity within the group.