Data from: Approximate Bayesian computation reveals the crucial role of oceanic islands for the assembly of continental biodiversity

The perceived low levels of genetic diversity, poor interspecific
competitive and defensive ability, and loss of dispersal capacities of
insular lineages have driven the view that oceanic islands are
evolutionary dead ends. Focusing on the Atlantic bryophyte flora
distributed across the archipelagos of the Azores, Madeira, the Canary
Islands, Western Europe, and northwestern Africa, we used an integrative
approach with species distribution modeling and population genetic
analyses based on approximate Bayesian computation to determine whether
this view applies to organisms with inherent high dispersal capacities.
Genetic diversity was found to be higher in island than in continental
populations, contributing to mounting evidence that, contrary to
theoretical expectations, island populations are not necessarily
genetically depauperate. Patterns of genetic variation among island and
continental populations consistently fitted those simulated under a
scenario of de novo foundation of continental populations from insular
ancestors better than those expected if islands would represent a sink or
a refugium of continental biodiversity. We, suggest that the northeastern
Atlantic archipelagos have played a key role as a stepping stone for
transoceanic migrants. Our results challenge the traditional notion that
oceanic islands are the end of the colonization road and illustrate the
significant role of oceanic islands as reservoirs of novel biodiversity
for the assembly of continental floras.