Evolution of plant biodiversity.

Biodiversity can be observed with all levels of organization of life forms. Species diversity is one level and molecular measurements of population structures reveal another level of biodiversity. However, in biodiversity assessments also other parameters such as the morphology and local adaptations of plants as well as habitat characteristics, including ecological and geological data, have to be considered. Thus, biodiversity is more than counting species and cannot be characterized by a single number. The dynamic nature of the evolution of biodiversity, gain and loss of traits or species is highlighted by two examples concerning spatial genetic population structures and speciation in Melampyrum and the evolution of a morphological novelty in the Solanaceae, the Chinese lantern Physalis floridana. Threats to biodiversity including human activities, like agriculture, are also discussed.