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Aim Four factors (time, dispersal, extinction and speciation) shape the differences in species richness within a clade between two regions. The southern African summer-rainfall 'Highveld' is less species rich than the adjacent winter-rainfall 'Greater Cape Floristic Region'. In many clades, this may be the result of a Cape origin of these temperate clades, with later dispersal to the cool uplands of the Highveld. We explored an alternative scenario of a widespread southern African Miocene temperate flora, which survived in the Cape. We used these four factors to seek the more likely scenario for the Danthonioideae. Location Southern Africa. Methods We used a rate-corrected and dated phylogeny including 118 of 134 species of African Danthonioideae (Poaceae), and assigned the species to be either winter rainfall (Cape) or summer rainfall (Highveld). We inferred speciation and extinction rates using TreePar and bamm for the whole clade and also for each rainfall regime, transition direction using BayesTraits and Lagrange, and integrated speciation-extinction-migration using Bi SSE. Results We found no differences in the speciation rates between the two areas, and no clear indication of the ancestral area of the clade. However, one of the most likely Bi SSE models found a lower extinction rate in the Cape, and another found a higher transition rate from summer rainfall to winter rainfall. Main conclusions We found more support for the scenario of a southern African rather than a Cape origin of the danthonioids. The winter rainfall Cape became differentiated from the rest of southern Africa in the late Miocene. Late Miocene extinction, possibly driven by the expansion of C4 grasses, may have decimated the Highveld lineages, whereas the Cape lineages continued to diversify. Exploring some other Cape clades may reveal more instances of the Cape acting as a 'museum' of southern African temperate diversity. [ABSTRACT FROM AUTHOR]

Much attention has been paid to the effects of climate change on species' range reductions and extinctions. There is however surprisingly little information on how climate change driven threat may impact the tree of life and result in loss of phylogenetic diversity ( PD). Some plant families and mammalian orders reveal nonrandom extinction patterns, but many other plant families do not. Do these discrepancies reflect different speciation histories and does climate induced extinction result in the same discrepancies among different groups? Answers to these questions require representative taxon sampling. Here, we combine phylogenetic analyses, species distribution modeling, and climate change projections on two of the largest plant families in the Cape Floristic Region (Proteaceae and Restionaceae), as well as the second most diverse mammalian order in Southern Africa (Chiroptera), and an herbivorous insect genus ( Platypleura) in the family Cicadidae to answer this question. We model current and future species distributions to assess species threat levels over the next 70 years, and then compare projected with random PD survival. Results for these animal and plant clades reveal congruence. PD losses are not significantly higher under predicted extinction than under random extinction simulations. So far the evidence suggests that focusing resources on climate threatened species alone may not result in disproportionate benefits for the preservation of evolutionary history. [ABSTRACT FROM AUTHOR]

The floras of the Mediterranean-climate areas of southern Africa and southwestern Australia are remarkably species rich. Because the two areas are at similar latitudes and in similar positions on their respective continents, they have probably had similar Cenozoic climatic histories. Here we test the prediction that the evolution of the species richness in the two areas followed a similar temporal progression by comparing the rates of lineage accumulation for African and Australian Restionaceae. Restionaceae (Poales) are typical and often dominant elements in the fynbos vegetation of the Cape Floristic Region of southern Africa and the kwongan vegetation of the Southwestern Floristic Province of Western Australia. The phylogeny of the family was estimated from combined datasets for rbcL and trnL-F sequences and a large morphological dataset; these datasets are largely congruent. The monophyly of Restionaceae is supported and a basal division into an African clade (∼350 species) and an Australian clade (146 species) corroborated. There is also support for a futher subdivision of these two large sister-clades, but the terminal resolution within the African clade is very weak. Fossil pollen records provided a minimum age of the common ancestor of Australian and African Restionaceae as 64-71 million years ago, and this date was used to calibrate a molecular clock. A molecular clock was rejected by a likelihood ratio test; therefore, rate changes between the lineages were smoothed using nonparametric rate smoothing. The rate-corrected ages were used to construct a plot of lineages through time. During the Palaeogene the Australian lineage diversity increased consistent with the predictions of the constant birthrate model, while the African lineage diversity showed a dramatic increase in diversification rate in the Miocene. Incomplete sampling obscures the patterns in the Neogene, but extending the trends to the modern extant diversity suggests that this... [ABSTRACT FROM AUTHOR]