Origin and diversification of the california flora: re-examining classic hypotheses with molecular phylogenies.
Författare
Summary, in English
The California Floristic Province exhibits one of the richest floras on the planet, with more than 5500 native plant species, approximately 40% of which are endemic. Despite its impressive diversity and the attention it has garnered from ecologists and evolutionary biologists, historical causes of species richness and endemism in California remain poorly understood. Using a phylogenetic analysis of 16 angiosperm clades, each containing California natives in addition to species found only outside California, we show that CA's current biodiversity primarily results from low extinction rates, as opposed to elevated speciation or immigration rates. Speciation rates in California were lowest among Arcto-Tertiary lineages (i.e., those colonizing California from the north, during the Tertiary), but extinction rates were universally low across California native plants of all historical, geographic origins. In contrast to long-accepted ideas, we find that California diversification rates were generally unaffected by the onset of the Mediterranean climate. However, the Mediterranean climate coincided with immigration of many desert species, validating one previous hypothesis regarding origins of CA's plant diversity. This study implicates topographic complexity and climatic buffering as key, long-standing features of CA's landscape favoring plant species persistence and diversification, and highlights California as an important refuge under changing climates.
Avdelning/ar
Publiceringsår
2013
Språk
Engelska
Sidor
1041-1054
Publikation/Tidskrift/Serie
Evolution
Volym
67
Issue
4
Dokumenttyp
Artikel i tidskrift
Förlag
Wiley-Blackwell
Ämne
- Biological Sciences
Nyckelord
- extinction
- Biogeography
- fossils
- macroevolution
- phylogenetics
- speciation
Status
Published
Forskningsgrupp
- Molecular Ecology and Evolution Lab
ISBN/ISSN/Övrigt
- ISSN: 1558-5646