![]() For steps three and four, cell-size and climatic threshold were established after several trials in order to retain as many points as possible while eliminating aberrant observations. Then, for every species and climatic variable, we retained points that were within 1.5 times the interquartile range. This was done by extracting the value of annual mean temperature and temperature annual range from WorldClim Global Climate Dataset v.2.0 (Fick & Hijmans, 2017) for every point. Fourth, points were eliminated that were clearly outside the climatic range of the species. Third, because spatial clustering as a result of sampling bias can influence climatic niche analyses, we randomly retained one point per species and per cell of a 2.5-minute spatial resolution raster (about 4.5 km at the equator). Second, for each species, all occurrences were plotted and points falling outside its known range were manually excluded. First, we eliminated all duplicate records and corrected the taxonomy following Bauters et al. GBIF is the largest repository of digitised occurrences information, however, it is necessary to apply certain filtering steps to minimize error in posterior analyses (Spalink et al., 2016). Accessions sequenced per marker, ITS: 137, ndhF: 136, rps16: 135.Īll georeferenced entries of Scleria available on the Global Biodiversity Information Facility (, 2018) were downloaded. Approximately 48 of 112 (43%) American species (areas: South, Central and North America), 72 of 105 (69%) African species (Africa and Madagascar), and 20 of 58 (34%) Asian and Oceanian species (Eurasia and Oceania). The sampling includes four species of tribe Bisboeckelereae, sister to tribe Sclerieae, and 140 accepted Scleria taxa (representing 53% of Scleria species). ![]() MethodsĭNA sequence data of three markers (ITS, ndhF, rps16) generated in previous studies (Bauters et al., 2016, 2018 Galán Díaz, 2017 Semmouri et al., 2019) are used in this study. Within subgenus Scleria, colonisations of Asia and Madagascar by sections Elatae and Abortivae, respectively, are coupled with niche shifts suggesting that these colonisations involved climate niche adaptation. Shifts in climate niche evolution predate the second shift in diversification rates suggesting lineages were pre-adapted prior to biogeographic movements. Main conclusions: Dispersification from South America to Africa without climate niche shift seems to explain the diversification shift in section Hypoporum implying that species were pre-adapted. ![]() Two main shifts in diversification rates happened during the warm period of the Miocene. 7) and Central America to South America (c. Main dispersal and colonisation events involve movements from South to Central America (c. Results: High dispersal rates in Scleria, a genus with multiple dispersal syndromes, make reconstruction of ancestral areas at deep nodes in the phylogeny highly equivocal. Integrating data from 12,978 digitised and georeferenced herbarium records, we investigated niche evolution. ![]() Methods: We used molecular data from three DNA regions sequenced for 278 accessions representing 140 Scleria taxa (53% of species) to develop a chronogram, model ancestral ranges, and measure rates of diversification. We investigate patterns of diversification in Scleria, and whether they are coupled with colonisation events, climate niche shifts or both. 250 species and has a pantropical distribution suggesting an extraordinary capacity for long-distance dispersal and colonisation. Aim: Colonisation of new areas may entail shifts in diversification rates linked to biogeographic movement (dispersification), which may involve niche evolution if species were not pre-adapted to the new environments.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |