Unparalleled rates of species diversification in Europe

Abstract

The most rapid species radiations have been reported from 'evolutionary laboratories', such as the Andes and the Cape of South Africa, leading to the prevailing view that diversification elsewhere has not been as dramatic. However, few studies have explicitly assessed rates of diversification in northern regions such as Europe. Here, we show that carnations (Dianthus, Caryophyllaceae), a well-known group of plants from temperate Eurasia, have diversified at the most rapid rate ever reported in plants or terrestrial vertebrates. Using phylogenetic methods, we found that the majority of species of carnations belong to a lineage that is remarkably species-rich in Europe, and arose at the rate of 2.2 -7.6 species per million years. Unlike most previous studies that have inferred rates of diversification in young diverse groups, we use a conservative approach throughout that explicitly incorporates the uncertainties associated with phylogenetic inference, molecular dating and incomplete taxon sampling. We detected a shift in diversification rates of carnations coinciding with a period of increase in climatic aridity in the Pleistocene, suggesting a link between climate and biodiversity. This explosive radiation suggests that Europe, the continent with the world's best-studied flora, has been underestimated as a cradle of recent and rapid speciation.

Eocene habitat shift from saline to freshwater promoted Tethyan amphipod diversification

“…The rate of freshwater Gammarus is comparable with fastest-diversifying bivalves 0.09 sp/My (17) and ground beetles 0.10 sp/My (18). However, it is slower than that of Mediterranean plants, such as Dianthus carnations, which have a rate of 2.2-7.6 sp/My (19), and Brassicaceae mustard 0.18-0.22 sp/My (20). The ancient Tethyan region is one of the hotspots of global biodiversity for both terrestrial and aquatic ecosystems.…”

The silent extinction: climate change and the potential hybridization-mediated extinction of endemic high-mountain plants

“…Nevertheless, we have found that most hybridizing species are non-relict, and are interbreeding with phylogenetically related species ( Table 2). As a consequence of the rapid diversification rate undergone by many Mediterranean plant lineages, many allopatric endemic species with weak reproductive isolation exist (Valente et al 2010;Gutiérrez-Larena et al 2002). Under these circumstances, we presume that the observed hybridization will lead to introgression.…”

“…One main feature of the Mediterranean flora is its high rate of diversification, with most of the current diversity in this region having evolved very recently as the consequence of the segregation of widespread taxa into populations isolated on the many mountaintops that form the complex Mediterranean landscape (Valente et al 2010). Most Mediterranean high-mountain plants therefore belong to young lineages with related species inhabiting the surrounding lowlands, a feature that may enhance the probability of hybridization after secondary contact.…”

Draba bruce-bennettii(Brassicaceae), a Remarkable New Species from Yukon Territory, Canada

“…2, Test 1; Appendix S4) represent three major phylogenetic clades (rosids, caryophyllids, and asterids) that have undergone recent, explosive radiations (e.g., Liu et al, 2006;Valente et al, 2010;Zhang et al, 2017b). These groups were the main consideration during design of the standard primer sets because they represent so much plant diversity at the species level.…”