Abstract
Premise of the study Universal probesets for targeted sequence capture have facilitated phylogenomic research into diverse plant groups with limited genomic resources, including from low-quality DNA typical of herbarium specimens. Here, we leverage the Angiosperms353 loci to infer the first phylogeny of Otoba (Myristicaceae), a Neotropical tree genus that is ecologically dominant in low-to-mid elevation wet forests, exclusively from herbarium specimens.
Methods We use a combination of Angiosperms353 loci, obtained via targeted sequence capture, and plastid sequences to resolve the phylogeny of Otoba using concatenated and species tree methods. We subsequently use this phylogeny to infer biogeography and trait evolution using phylogenetic comparative methods.
Key results Recovery success of loci is correlated with age of herbarium specimens and average annual precipitation. Despite a large amount of missing data, we resolve the phylogeny of Otoba into three major subclades, each structured by geography. We show that Otoba’s crown radiation occurred on the western slopes of the Andes in the late Miocene, and from there, migrated into Central America at least twice; the genus was only able to cross to the eastern slopes of the Andes a single time. Trait evolution has been dynamic across vegetative and reproductive traits, with multiple origins of most discrete traits investigated, including ecologically important aril color.
Conclusions Otoba is recent, rapid radiation whose evolution is tied to landscape change, including Andean uplift, in the northern Neotropics. Its dynamic morphological evolution is consistent with sorting of ancestral traits during recent speciation events. In one of the first herbariomic studies exclusively using herbarium tissue from specimens collected in the wet tropics, this study demonstrates the promise of Angiosperms353 loci in resolving shallow species-level relationships, even from low-quality DNA.
Competing Interest Statement
The authors have declared no competing interest.
