Data from: Testing the link between population genetic differentiation and clade diversification in Costa Rican orchids

Species population genetics could be an important factor explaining
variation in clade species richness. Here we use newly generated AFLP data
to test whether five pairs of sister clades of Costa Rican orchids that
differ greatly in species richness also differ in average neutral genetic
differentiation within species, expecting that if the strength of
processes promoting differentiation within species is phylogenetically
heritable, then clades with greater genetic differentiation should
diversify more. Contrary to expectation, neutral genetic differentiation
does not correlate directly with total diversification in the clades
studied. Neutral genetic differentiation varies greatly among species and
shows no heritability within clades. Half of the variation in neutral
genetic differentiation among populations can be explained by ecological
variables, and species-level traits explain the most variation.
Unexpectedly, we find no isolation by distance in any species, but genetic
differentiation is greater between populations occupying different niches.
This pattern corresponds with those observed for microscopic eukaryotes
and could reflect effective widespread dispersal of tiny and numerous
orchid seeds. Although not providing a definitive answer to whether
population genetics processes affect clade diversification, this work
highlights the potential for addressing new macroevolutionary questions
using a comparative population genetic approach.