Enhancing the survival and expansion potential of a founder population through clonality

• Although founder populations often have low diversity, they can potentially serve as stepping stones for further colonization, as refugia during nonoptimal times and as a source of specialized adaptive potential. The demonstration of such potential within natural plant populations has proven to be particularly difficult. Our investigation into a geographically disjunct population of a heterostylous shrub, Erythroxylum pusillum, aims to explore the evolutionary and ecological consequences of being an isolated founder population. • Microsatellite-based analyses were used to find evidence for, and trace the origins of, a severe founder effect. Molecular and spatial evidence was used to quantify clonality and to discover proof of somaclonal mutations. • We describe the unprecedented case of an isolated population that persisted through historical environmental fluctuations and in marginal habitat through vegetative spread, and is counteracting the lack of sexual recombination and gene flow through somatic mutation. • Our findings advance our understanding of how founder populations survive, differentiate and evolve. They also have implications for how conservation agencies should perceive and manage previously considered 'dead-end' populations.