Phylogenomic relationships and historical biogeography in the South American vegetable ivory palms (Phytelepheae)

Abstract

The vegetable ivory palms (Phytelepheae) form a small group of Neotropical palms whose phylogenetic relationships are not fully understood. Three genera and eight species are currently recognized; however, it has been suggested that Phytelephas macrocarpa could include the species Phytelephas seemannii and Phytelephas schottii because of supposed phylogenetic relatedness and similar morphology. We inferred their phylogenetic relationships and divergence time estimates using the 32 most clock-like loci of a custom palm bait-kit formed by 176 genes and four fossils for time calibration. We additionally explored the historical biogeography of the tribe under the recovered phylogenetic relationships. Our fossil-dated tree showed the eight species previously recognized, and that P. macrocarpa is not closely related to P. seemanii and P. schottii, which, as a consequence, should not be included in P. macrocarpa. The ancestor of the vegetable ivory palms was widely-distributed in the Choco, the inter-Andean valley of the Magdalena River, and the Amazonia during the Miocene at 19.25 Ma. Early diversification in Phytelephas at 5.27 Ma can be attributed to trans-Andean vicariance between the Choco/Magdalena and the Amazonia. Our results support the role of Andean uplift in the early diversification of Phytelephas under new phylogenetic relationships inferred from genomic data.