Dynamics of evolution in Irano-Anatolian and Caucasus biodiversity hotspots: Evolutionary radiation and its drivers inGypsophila(Caryophyllaceae)

Abstract

SummaryIrano-Anatolian and Caucasus biodiversity hotspots, characterized by a high degree of alpine endemism and extremely dynamic geographical history, are among the 36 globally defined biodiversity hotspots. However, the dynamics of evolution and the cofactors of diversification have not been investigated in these regions.We explore the evolutionary dynamics ofGypsophila(Caryophylleae: Caryophyllaceae), a large and diverse genus with a high degree of endemism in the Irano-Anatolian and Caucasus biodiversity hotspots. We investigate the diversification rate and its biotic and abiotic cofactors within the Caryophylleae tribe, with a special focus onGypsophila.We identified a shift in the diversification rate ofGypsophilathat started about 3 million years ago and was influenced by both biotic and abiotic forces. The results suggest that the diversity insideGypsophilaevolved due to evolutionary radiation that was triggered by both paleoenvironmental factors and acquiring morphological novelties.The result of this study demonstrates a highly dynamic evolutionary history across the Caryophylleae clade andGypsophila, which is consistent with the extensive fluctuation in the geological and climatological history of Irano-Anatolian and Caucasus biodiversity hotspots. This study significantly improves our understanding of the dynamics of evolution in the Irano-Anatolian and Caucasus biodiversity hotspots and the impact of environmental changes on the rate of diversification.