Change search
ReferencesLink to record
Permanent link

Direct link
Evolution and diversification related to rainfall regimes: diversification patterns in the South African genus Metalasia (Asteraceae-Gnaphalieae)
Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
2015 (English)In: Journal of Biogeography, ISSN 0305-0270, E-ISSN 1365-2699, Vol. 42, no 1, 121-131 p.Article in journal (Refereed) Published
Abstract [en]

AimThe Cape region is known for its exceptional species richness, although much remains unknown regarding the appearance of the modern Cape flora. One explanation is that floral diversification was influenced by the establishment of winter rainfall/summer arid conditions hypothesized to have occurred towards the end of the Miocene. We studied the evolution and diversification of the plant genus Metalasia (Asteraceae-Gnaphalieae), with the aim of testing whether radiation patterns may have been influenced by the climatic changes. LocationSouth Africa, with emphasis on the south-west. MethodsThe radiation of Metalasia was investigated using two approaches: a species diffusion approach, which estimated the ancestral areas by means of a relaxed random walk while sampling from extant distributions; and a discrete approach, in which distributions were defined according to the phytogeographical centres of the Cape region. Secondarily derived clock rates from an earlier Gnaphalieae study were used for calibration purposes. ResultsOur analyses date Metalasia to approximately 6.9Ma, after the Miocene-Pliocene boundary and the establishment of the winter rainfall/summer arid conditions. Metalasia consists of two sister clades: Clade A and Clade B. Clade B, which is endemic to the winter rainfall area, is estimated to have diversified c. 6.4Ma, whereas Clade A, with a main distribution in the all-year rainfall area, is considerably younger, with a crown group age estimated to 3.3Ma. Diversification rates suggest an early rapid speciation, with rates decreasing through time both for Metalasia and for clades A and B separately. Ancestral area estimations show a possible scenario for the radiation of Metalasia to its current diversity and distribution, with no conflict between results inferred from diffusion or discrete methods. Main conclusionsThe diversification of Metalasia is estimated to have begun after the establishment of the winter rainfall/summer arid conditions, consistent with its radiation having been influenced by changes in the climatic regime.

Place, publisher, year, edition, pages
2015. Vol. 42, no 1, 121-131 p.
Keyword [en]
Biogeography, Cape flora, Cape Floristic Region, diversity, Metalasia, South Africa, species-tree diffusion, winter rainfall
National Category
Earth and Related Environmental Sciences Biological Sciences
URN: urn:nbn:se:su:diva-113113DOI: 10.1111/jbi.12390ISI: 000346069700012OAI: diva2:790250


Available from: 2015-02-23 Created: 2015-01-23 Last updated: 2015-02-23Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Bengtson, AnnikaKaris, Per Ola
By organisation
Department of Ecology, Environment and Plant Sciences
In the same journal
Journal of Biogeography
Earth and Related Environmental SciencesBiological Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 77 hits
ReferencesLink to record
Permanent link

Direct link