Evolutionary dynamics in Irano-Anatolian and Caucasus biodiversity hotspots: Evolutionary radiation and its drivers in Gypsophila (Caryophyllaceae)

● Diversification rates vary through time, with bursts of rapid diversification underscoring species richness across the Tree of Life. Yet the abiotic and biotic factors that correlate with periods of rapid diversification are not well known. ● We explored the diversification dynamics of Gypsophila (Caryophylleae: Caryophyllaceae), a large and diverse genus with a high degree of endemism in the Irano-Anatolian and Caucasus biodiversity hotspots. We tested the hypothesis of young and recent diversification of biodiversity in these two hotspots and investigated the biotic and abiotic, and paleoenvironmental cofactors of diversification within the Caryophylleae tribe, with a special focus on Gypsophila . ● Our analysis identified multiple shifts in the diversification rate within Caryophylleae, including a newly identified shift in Gypsophila , which began approximately 3 million years ago and was triggered by both paleoenvironmental factors and morphological novelties. These novelties were enabled by explosive diversification of woodiness and perenniality and were facilitated through the high adaptability of Gypsophila to gypsum soil and the harsh environments of alpine habitats. ● These findings reveal the highly dynamic evolutionary history of both the Caryophylleae clade and Gypsophila , consistent with the extensive historical fluctuations in the geology and climate of the 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 highlights the impact of environmental changes and morphological innovations on diversification rates.