Long-distance dispersal shaped the diversity of tribe Dorstenieae (Moraceae)

Abstract

1 Aim: The Neotropics have the highest terrestrial biodiversity on earth. Investigating the 2 relationships between the floras of the Neotropics and other tropical areas is critical to 3 understanding the origin and evolution of this mega-diverse region. Tribe Dorstenieae (Moraceae) 4 has a pantropical distribution and almost equal number of species on both sides of the Atlantic.5In this study, we investigate the relationship between the African and Neotropical floras using 6 Dorstenieae (15 genera, 156 species, Moraceae) as a model clade. 7 Location: the Neotropics and Africa. 8 Methods: We used a targeted enrichment strategy with herbarium samples and a nuclear bait set 9 to assemble a data set of 102 genes sampled from 83 (53%) species and fifteen genera (100%) of 10 Dorstenieae, and five outgroup species. Phylogenetic relationships were reconstructed with 11 maximum likelihood and coalescent approaches. This phylogeny was dated with a Bayesian 12 relaxed clock model and four fossil calibrations. The biogeographic history of the group was 13 then reconstructed with several dispersal-extinction-cladogenesis models (incl. DEC and DEC+J).14 Results: The crown-group ages of Dorstenieae and Dorstenia were estimated in the Cretaceous 15 (65.8-79.8 Ma) and the Paleocene (50.8-67.3 Ma), respectively. Tribe Dorstenieae as a whole 16 appears to have originated in the joint area of continental Africa, Madagascar and Asia-Oceania 17 area. The Neotropical species of Dorstenia diversified in the Eocene (29.8-44.7 Ma) and formed a 18 clade nested within the African lineages in the genus. Brosimum s.l., with a crown-group age at 19 the period of the Oligocene and Miocene (14.9-31.1 Ma), represents another Neotropical clade in 20 Dorstenieae. Main conclusions: Tribe Dorstenieae originated in the joint area of continental Africa, 1 Madagascar and Asia-Oceania area in the Cretaceous and then dispersed into Neotropics twice. 2 Neotropical diversification after long-distance dispersal across the Atlantic is the most plausible 3 explanation for the extant distribution pattern of Dorstenieae.4 5

Phylogenomics of Brosimum (Moraceae) and allied genera, including a revised subgeneric system

“…This has led to conflicting views of phylogenetic relationships within the tribe (Berg, 2001; Clement & Weiblen, 2009; Zerega & al., 2010; Gardner & al., in press). A recent phylogenomic study of Dorstenieae, based on a target enrichment approach (Q. Zhang & al., 2019a), confirmed the monophyly of Dorstenieae, which includes Brosimum together with 15 other genera (Zerega & Gardner, 2019; Gardner & al., in press). These include members of the now‐obsolete Brosimeae as well as others ( Bleekrodea Blume, Broussonetia L'Hér.…”

“…(2016), Q. Zhang & al. (2019a), and the National Center for Biotechnology Information (NCBI) Sequence Read Archive (SRA) to complete the outgroup sampling. All new reads have been deposited in the SRA (BioProject PRJNA322184).…”

“…We time‐calibrated the Brosimum phylogenetic tree with three fossils (for full details, see Q. Zhang & al., 2019a) and two secondary calibrations. The fossil wood of Artocarpoxylon deccanensis Mehrotra & al.…”

“…Uncertainty as to phylogenetic relationships, morphological evolution, and biogeographic history remained, however, due to the small number of sequences and incomplete taxon sampling employed in previous studies. As part of a broader investigation into relationships within the Dorstenieae (Q. Zhang & al., 2019a), we employed a phylogenomic approach to investigate the evolutionary history of the genera in the “Brosimeae”.…”

Phylogenomics ofBrosimumSw. (Moraceae) and allied genera, including a revised subgeneric system

“…Previous phylogenetic work including Brosimum includes a two-locus family-level study 124 (with five Brosimum species) based on nuclear ribosomal and chloroplast DNA (Zerega & al.,125 2005; Clement & Weiblen, 2009), a targeted study (12 Brosimum species) based on a single 126 chloroplast locus (Silva, 2007), and a tribe-level study (10 Brosimum species) using a target 127 enrichment approach (Zhang & al., 2019a). They all found that Trymatoccocus and 128…”