Aim The Tibetan Plateau (TP) hosts many endemic species, but questions regarding when and from where these species originated have not been comprehensively answered. Here, we provide a synthesis of the biogeographical history of terrestrial vertebrates endemic to the TP and investigate the potential drivers of their spatio-temporal origins.

Location Tibetan Plateau and its surrounding regions

Time period Cenozoic

Major taxa studied Terrestrial vertebrates

Methods We used dispersal–extinction–cladogenesis models based on time-calibrated phylogenies to reconstruct the ancestral ranges of 174 endemic TP species and compiled the ancestral ranges and age estimates of their dispersal events. We generated a possibility map of source areas for endemic TP species by counting the incidence of non-TP sister clades in 110 km × 110 km grid cells. We used generalized linear mixed models to assess the relative importance of historical processes and environmental factors in explaining the geographical variations in the source areas. We created subsets based on four vertebrate classes to test whether the dispersal events varied spatially and temporally among taxonomic groups.

Results We found that the endemic species colonised the TP as early as 55 Ma, and that the main colonisation phase started to increase around 15 Ma and peaked after 6 Ma. The major source areas of endemic TP species include the Hengduan Mountains, the Himalayas, and Central Asia. Elevation difference had the strongest effect on the source areas, followed by geographical distance. The spatio-temporal origins of species endemic to the TP and the potential drivers showed significant differences among vertebrate classes.

Main conclusions Our study supports the hypothesis that endemic TP species originated from various zoogeographical regions at different times and highlights the important roles of the TP uplift and past climatic changes for determining the spatio-temporal origins of endemic TP species.

We compiled a checklist of terrestrial vertebrates endemic to the TP according to the species distribution data against the TP’s geographical range. The species geographical ranges were obtained from the IUCN Red List database (http://www.iucnredlist.org) for mammals and amphibians, BirdLife International and NatureServe (http://www.birdlife.org) for birds, and Roll et al. (2017) for reptiles. We combined the geographical range data with the Global Biodiversity Information Facility (GBIF; http://www.gbif.org) and Fauna of China to validate the checklist of endemic TP species. Finally, we identified 178 terrestrial vertebrates endemic to the TP, including 68 mammals, 57 birds, 23 reptiles, and 30 amphibians.

We obtained dated phylogenies from Upham, Esselstyn, & Jetz (2019) for mammals, Jetz et al. (2014) for birds, Tonini, Beard, Ferreira, Jetz, & Pyron (2016) for reptiles, and Jetz & Pyron (2018) for amphibians. These phylogenies are available online (http://vertlife.org/phylosubsets) as the posterior distribution of trees (n = 1,000), and we built maximum clade credibility phylogenies using the ‘phangorn’ package (Schliep, 2011) in R version 3.6.0 (R Development Core Team, 2019). The number of endemic TP species that could be matched to the tips in the phylogenies was 174 (out of the 178 species).

This zip package contains the data and R code supporting the findings of the following paper: He et al. Geological and climatic histories likely shaped the origins of terrestrial vertebrates endemic to the Tibetan Plateau