Insights on the evolutionary origin of Detarioideae, a clade of ecologically dominant tropical African trees.
African tropical forests are generally considered less diverse than their Neotropical and Asian counterparts. By contrast, the Detarioideae is much more diverse in Africa than in South America and Asia. To better understand the evolution of this contrasting diversity pattern, we investigated the biogeographical and ecological origin of this subfamily, testing whether they originated in dry biomes surrounding the Tethys Seaway as currently hypothesized for many groups of Leguminosae. We constructed the largest time-calibrated phylogeny for the subfamily to date, reconstructed ancestral states for geography and biome/habitat, estimated diversification and extinction rates, and evaluated biome/habitat and geographic shifts in Detarioideae. The ancestral habitat of Detarioideae is postulated to be a primary forest (terra firme) originated in Africa-South America, in the early Palaeocene, after which several biome/habitat and geographic shifts occurred. The origin of Detarioideae is older than previous estimates, which postulated a dry (succulent) biome origin according to the Tethys Seaway hypothesis, and instead we reveal a post Gondwana and terra firme origin for this early branching clade of legumes. Detarioideae include some of the most dominant trees in evergreen forests and have likely played a pivotal role in shaping continental African forest diversity.
Comparative Plant and Fungal Biology Department, Royal Botanic Gardens, Kew, Richmond, TW9 3DS, UK.|Institut de recherche en biologie végétale and Département de Sciences biologiques, Université de Montréal, 4101 Sherbrooke est, Montréal, QC, H1X 2B2, Canada.
Manuel
M
de la Estrella
Comparative Plant and Fungal Biology Department, Royal Botanic Gardens, Kew, Richmond, TW9 3DS, UK.
Félix
F
Forest
Naturalis Biodiversity Centre, National Herbarium of the Netherlands, Darwinweg 2, 2333, CR Leiden, the Netherlands.
Jan J
JJ
Wieringa
Institut de recherche en biologie végétale and Département de Sciences biologiques, Université de Montréal, 4101 Sherbrooke est, Montréal, QC, H1X 2B2, Canada.|Université de Toulouse, EDB (Laboratoire Evolution et Diversité Biologique), UMR5174, F-31062, Toulouse, France.|CNRS, UPS, EDB (Laboratoire Evolution et Diversité Biologique), UMR5174, 118 route de Narbonne, F-31062, Toulouse, France.
Marie
M
Fougère-Danezan
Institut de recherche en biologie végétale and Département de Sciences biologiques, Université de Montréal, 4101 Sherbrooke est, Montréal, QC, H1X 2B2, Canada.
Anne
A
Bruneau
D000349:Africa; D005075:Biological Evolution; D017753:Ecosystem; D053476:Extinction, Biological; D007887:Fabaceae / Q000502:physiology*; D010802:Phylogeny; D058974:Phylogeography; D014197:Trees; D014329:Tropical Climate
Fabaceae; biogeography; biome evolution; diversification rates; mono-dominant forests; niche conservatism; tropical forests