Afro-alpine flagships revisited: Parallel adaptation, intermountain admixture and shallow genetic structuring in the giant senecios (Dendrosenecio).

摘要: Distantly related lineages of the enigmatic giant rosette plants tropical alpine environments provide classical examples convergent adaptation. For senecios (Dendrosenecio), endemic landmarks East African sky islands, it has also been suggested that parallel adaptation important for within-lineage differentiation. To test this hypothesis and to address potential gene flow hybridization among isolated we organized field expeditions all major mountains. We sampled currently accepted species but one subspecies genotyped 460 representing 109 populations. tested whether genetic structuring corresponds geography, as predicted by a hypothesis, or altitudinal belt habitat rather than mountains, single origin adaptations. Bayesian Neighbor-Net analyses showed main structure is shallow largely supporting recent, rapid radiation via altitude/habitat on different found evidence intermountain admixture, suggesting several long-distance dispersals wind across vast areas unsuitable habitat. The combination adaptation, secondary contact, may explain complex patterns morphological variation contradicting taxonomic treatments these rare giants, use wide concepts. Notably, within-population diversity was very low calls increased conservation efforts.