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.
all spp AFLP allele tables
Final AFLP allele tables for all study species. See Readme and manuscript for more details.
additional.study.species.ecology.fordryad
Additional ecological data for all study species. See the general Readme and manuscript for more details.
pairwise.data.fordryad
Pairwise data for comparisons of study populations - population genetic distances, geographical distances, and enviromental differences. See general Readme and manuscript for more details.
pop.code.legend.fordryad
Explanation of population codes used in some of the data files here on Dryad.
sample.data.fordryad
Branch circumference and other data for all samples used in analyses. See general Readme and manuscript for more details.
studyclade.ecol.bysp.fordryad
Ecological data for all species from Costa Rica within the study clades. See general Readme and manuscript for more details.
studyclade.range.size.bysp.fordryad
Range size data for all species within each study clade. See general Readme and manuscript for more details.
table.S1.fordryad
Table S1 from the Supplementary Materials - Voucher information for samples collected for this study and deposited at the Lankester Botanic Garden in Costa Rica.
table.S2.fordryad
Table S2 from the Supplementary Materials - Detailed description of each location where samples were collected.
table.S3.fordryad
Table S3 from the Supplementary Materials - Details of AFLP method used for each study species. A star by the number of preamplification PCR cycles indicates that a 2 min extension time was used instead of the standard 2.5 min.
table.S4.fordryad
Table S4 from the Supplementary Materials - Scoring analysis details for all analysed AFLP datasets. Datasets that had unacceptably high error rates were not used for analyses and are not listed here. unf. = unfiltered; fil. = filtered; abs. = absolute scoring threshold; rel. = relative scoring threshold.
table.S5.fordryad
Table S5 from the Supplementary Materials - GenBank accession numbers for newly-generated matK sequences and the collection numbers of the samples used to generate the sequences.
table.S6.fordryad
Table S6 from the Supplementary Materials - Ecological characteristics of study clades. Values for each clade are means of species values (using data from these files on Dryad: studyclade.ecol.bysp.fordryad.txt and studyclade.range.size.bysp.fordryad.txt). Species range size is measured as number of TDWG Level 2 regions.
table.S7.fordryad
Table S7 from the Supplementary Materials - Branch circumference mean and variance for all study species over all sampled plants from each species. Dryadella odontostele was only found growing on a branch once, and so no variance is given.
Readme
General readme giving further details on data files here on Dryad.