RadiPhyte · Advancing beyond the adaptive radiation paradigm: uncovering the contributions of adaptive and non-adaptive processes to a rapid plant radiation

Advancing beyond the adaptive radiation paradigm: uncovering the contributions of adaptive and non-adaptive processes to a rapid plant radiation

RadiPhyte focuses on a key question in evolutionary biology and a key aspect for our understanding of biodiversity through a ground-breaking investigation of the main triggers of one of the most rapid plant radiations known to science, the diversification of the genus Dianthus in Eurasia. The current paradigm on species radiations is that adaptation to different ecological niches together with the rise of phenotypic diversity trigger such rapid radiations. However, existing studies fail to test the alternative hypothesis, which is that rapid radiations could be also driven by non-adaptive processes mediated, for example by the geographic isolation of lineages with similar ecological niches. Therefore, in order to address the importance of adaptive versus non-adaptive processes in plant radiations, an evolutionary study of ecological and phenotypic differentiation in such a rapid radiation is required. Advanced genomic and phenotyping approaches, together with an accurate analytical framework, can reveal the processes that drive evolutionary radiations, and thereby enhance our understanding of macroevolution. We chose to work on the Dianthus of Eurasia because they are truly the “cichlids of the plant world”. The genus Dianthus comprises >330 species distributed throughout temperate Eurasia and Africa, with the bulk of its diversity (≥245 species) occurring in continental Eurasia. Dianthus displays a striking morphological diversity, indicating that ecological adaptation has probably contributed to its radiation. The rapid radiation of Dianthus further appears to coincide with increased aridity and seasonality in the Mediterranean and Irano-Turanian bioregions. The two bioregions where most Dianthus species occur, the Mediterranean and Irano-Turanian regions, are among the globe’s most topographically complex areas. They are home to >20% of the world’s plant species and represent hotspots of evolutionary and biological diversity of the Old World. The main objective of RadiPhyte was therefore to investigate the radiation patterns of the genus Dianthus through two simultaneous cutting-edge approaches: (1) modern high-throughput capture sequencing to generate a robust, fully resolved phylogeny of the genus and (2) phenotyping methods to acquire a vast 3D quantitative shape dataset of the flowers of the genus.

Data: CORDIS, © European Union