Testing the Tropical Niche Conservatism Hypothesis: Climatic Niche Evolution of Escallonia Mutis ex L. F. (Escalloniaceae)

• Published in: Plants (Basel) 2024-01, Vol.13 (1), p.133
• Main Authors: Dibán, María José, Hinojosa, Luis Felipe
• Format: Article
• Language: English
• Subjects: Altitude; ancestral area; Annual precipitation; Biogeography; Climate; Climate models; Climatic conditions; Conservation; ecological niche modelling; Eocene; Escallonia; Evolution; evolutionary models; Forests; Glaciers; Hypotheses; Niches; Paleoclimate; phylogenetic signal; Phylogenetics; Phylogeny; Precipitation; Range extension; Sea level; Temperature; the Andes
• ISSN: 2223-7747; 2223-7747
• DOI: 10.3390/plants13010133

We assess the Tropical Niche Conservatism Hypothesis in the genus in South America using phylogeny, paleoclimate estimation and current niche modelling. We tested four predictions: (1) the climatic condition where the ancestor of grew is megathermal; (2) the temperate niche is a derived condition from tropical clades; (3) the most closely related species have a similar current climate niche (conservation of the phylogenetic niche); and (4) there is a range expansion from the northern Andes to high latitudes during warm times. Our phylogenetic hypothesis shows that originated 52.17 ± 0.85 My, in the early Eocene, with an annual mean temperature of 13.8 °C and annual precipitation of 1081 mm, corresponding to a microthermal to mesothermal climate; the species of the northern and central tropical Andes would be the ancestral ones, and the temperate species evolved between 32 and 20 My in a microthermal climate. The predominant evolutionary models were Brownian and Ornstein-Uhlenbeck. There was phylogenetic signal in 7 of the 9 variables, indicating conservation of the climatic niche. would have originated in the central and southern Andes and reached the other environments by dispersion.