Global Palm Phylogeny
The palm family (Arecaceae) with its ca 2600 species has steadily developed into what is now probably the best model for studying tropical rain forest plant diversity (Couvreur & Baker 2013). Much of this success has been down to the availability of a solid phylogenetic tree of all palm genera (Baker et al. 2009). However, the use of such a sparsely sampled tree has obvious limits – for example, Couvreur et al. (2011) estimated that diversification dynamics between 24 Mya and now cannot be modelled. This is a shame, as much of the present-day variation in palm diversity (and tropical rain forest plant diversity in general) must have been shaped by Neogene climate change – alas, we cannot test this… yet.
A couple of years ago, we had a first stab at building a comprehensive species-level phylogeny of palms (Faurby et al. 2016). It was comprehensive in the sense that it included all available molecular data, plus some morphological data and taxonomic constraints – but it was by no means complete, with only 35% of the species having any DNA sequence data. Building this tree was an important step in the right direction (by the way, you can download it here), but maybe its most important function was to highlight how little we still know about species level palm phylogeny.
At the same time, groundbreaking work was being done on adapting phylogenomic methods for palms (Heyduk et al. 2016), and several projects (including our own on Madagascan palms) started using this approach, focusing on various palm clades. At the World Palm Symposium 2015 in Quindío, Colombia, we realised that if we managed to join up all those projects, a well-resolved species level phylogeny of the palms would come into reach. Thus, we founded the Palm Phylogeny Working Group (PPWG).
The PPWG consists of many complementary projects covering different parts of the palm family that are either geographically or taxonomically delineated. Most bits of the palm family are now being worked on by the PPWG, and thanks to new funding by the Aarhus University Research Foundation, we will be able to pull together a comprehensive species-level phylogenomic tree within the next three to five years. Then, finally, we will be able to properly analyse the dynamics of palm diversification in the Negoene!
Baker, W.J. et al. (2009). Complete Generic-Level Phylogenetic Analyses of Palms (Arecaceae) with Comparisons of Supertree and Supermatrix Approaches. Systematic Biology, 58, 240-256.
Couvreur, T.L.P. et al. (2011). Origin and global diversification patterns of tropical rain forests: inferences from a complete genus-level phylogeny of palms. BMC Biology, 9.
Couvreur, T.L.P. & Baker, W.J. (2013). Tropical rain forest evolution: palms as a model group. BMC Biol, 11:48
Faurby, S. et al. (2016). An all-evidence species-level supertree for the palms (Arecaceae). Molecular Phylogenetics and Evolution, 100, 57-69.
Heyduk, K. et al. (2016). Phylogenomic analyses of species relationships in the genus Sabal (Arecaceae) using targeted sequence capture. Biol J Linn Soc, 117, 106-120.