PRJNA386149
Malagasy Canarium species for phylogenetic analyses Raw sequence reads
While it is widely accepted that tropical forests are exceedingly diverse, challenges to species discovery and delimitation, such as limited samples of rare species and phenotypes, can result in misleading biodiversity estimates. Here, we developed an integrative approach for identifying independently evolving lineages in Canarium (Burseraceae), a dominant clade of rainforest trees in Madagascar with limited samples. Specifically, we integrate genotyping-by-sequencing (GBS), morphological, geographic, and climatic data. Hypotheses based on morphology alone have recognized anywhere from one to 33 endemic species. Our analyses support the existence of at least six distinct lineages, among which there has been occasional gene flow. An improved understanding of Canarium species diversity has important implications for conservation efforts and for understanding the genesis of diversity in Madagascar. The view is widespread that the addition of molecular evidence will increase the number of species, but in the case of Canarium the evidence presented here supports a significant decrease. This highlights our still limited understanding of diversity in tropical forests and the need for additional case studies.