Oral Paper

         Biogeography

Examining phylogenetic (dis)agreement with migration route hypotheses in tarflowers (Bejaria, Ericaceae)

Presenting Author
Senna Robeson
Description
Tarflowers (Bejaria, Ericaceae) are very common in Neotropical mountains, but exhibit notable range disjunctions across the Americas, with only a few scattered species found north of South America. A longstanding hypothesis is that the genus reached its present distribution by passage through Caribbean islands, making a subsequent secondary expansion into Central America. However, this has not been tested amid a paucity of recent work with the group. As biotic connectivity between continents via the Caribbean (such as in the GAARlandia hypothesis) has received little empirical support in recent research with other taxa, we set out to test whether any such connection is fundamentally congruent with species relationships in the group. A preliminary species tree based on target capture sequencing from herbarium specimens using Angiosperm 353 probes is presented here, representing around fifty individuals of at least 18 tarflower morphospecies from every region where the genus occurs. The tree topology suggests that a Central American over-land migration route is more likely to have led to the present-day distribution of the group. These early data also suggest that the Central American tarflowers are likely to require systematic revisions corresponding to the biogeographic entities revealed by the phylogeny. Further clarifying work is needed to pinpoint the timing of divergences, especially as there are no fossils available for the group, but this research begins to shed light on the origins of this little-studied but ecologically prominent genus.