Evolution of endemism on a young tropical mountain.

Tropical mountains are hot spots of biodiversity and endemism, but the evolutionary origins of their unique biotas are poorly understood. In varying degrees, local and regional extinction, long-distance colonization, and local recruitment may all contribute to the exceptional character of these communities. Also, it is debated whether mountain endemics mostly originate from local lowland taxa, or from lineages that reach the mountain by long-range dispersal from cool localities elsewhere.

Elucidating the evolutionary history of the Southeast Asian, holoparasitic, giant-flowered Rafflesiaceae: pliocene vicariance, morphological convergence and character displacement.

The aim of the present study is to elucidate the evolutionary history of the enigmatic holoparasitic Rafflesiaceae. More specifically, floral morphological evolution is interpreted in a molecular phylogenetic context, the biogeographic history of the family is investigated, and the possibility of character displacement to have been operating in this family is assessed. Parsimony and Bayesian methods are used to estimate phylogeny and divergence times among Rafflesiaceae species based on nuclear and mitochondrial DNA sequence data from Barkman et al.

Accelerated rates of floral evolution at the upper size limit for flowers.

Evolutionary theory explains phenotypic change as the result of natural selection, with constraint limiting the direction, magnitude, and rate of response [1]. Constraint is particularly likely to govern evolutionary change when a trait is at perceived upper or lower limits. Macroevolutionary rates of floral-size change are unknown for any angiosperm family, but it is predicted that rates should be diminished near the upper size limit of flowers, as has been shown for mammal body mass [2].

Mitochondrial DNA sequences reveal the photosynthetic relatives of Rafflesia, the world's largest flower.

All parasites are thought to have evolved from free-living ancestors. However, the ancestral conditions facilitating the shift to parasitism are unclear, particularly in plants because the phylogenetic position of many parasites is unknown. This is especially true for Rafflesia, an endophytic holoparasite that produces the largest flowers in the world and has defied confident phylogenetic placement since its discovery >180 years ago.