Climate and Speciation in the Mediterranean biome

The Mediterranean basin is one of the world's biodiversity hotspots yet patterns of distribution and diversification of species that are key to maintaining this biodiversity are still poorly understood. The rise in population and urban development makes the area at particular risk of biodiversity loss. We aim to develop a model system for the study of Mediterranean plant species in relation to geological and climatic history through the Cenozoic using Narcissus as an exemplar system. Recent meta-analyses (Escudero et al. 2017; Vargas et al. 2018) indicate Mediterranean species diversification may have started in the mid Cenozoic, before the formation of the Mediterranean climate zone. Limited availability of appropriate climate models to biologists has restricted the interpretation of diversification as a function of climate change in the pre-Mediterranean-climate period. The Narcissus centre of diversity is Iberia but spreads to North Africa and east through Asia as far as China. It is thought that the distribution is a result of the combined interactions of natural diversification over millions of years and later spread by man, possibly as much as six thousand years.

This project will develop ecological niche models for all Narcissus species and further develop the Narcissus phylogenetic tree through genomic data. Using the techniques of phyloclimatic modelling the project will bring together Narcissus phylogeny, niche preferences, and Cenozoic palaeoclimate models offering the opportunity to understand more general patterns of distribution in Mediterranean species. Previous work by Yesson & Culham on Cyclamen, in the Eastern Mediterranean suggested a range of physical factors including orogeny and climate influenced speciation that will be explored further in this project. The genetic patterns we are currently finding in Narcissus suggest there has been disruption to the distribution of the genus over varying geological timescales (unpublished) resulting in previously unreported genetic disjunctions between Morocco and northern Spain, a novel story in diversification of Mediterranean species.

The UoR in partnership with the RHS (the international registration authority for Narcissus cultivars) have developed molecular tools for population biology and molecular phylogenetics in Narcissus using microsatellite libraries and Illumina HiSeq PE150 genomic data. The team recently published the first complete Narcissus plastome (Könyves et al. 2018) and this SCENARIO project will develop the most comprehensive phylogeny yet built, including all sections of the genus. The collection of well-documented living plant material held by the team provides the basis for sampling.

The project will provide fundamental insights into:
1. Understanding of evolutionary patterns in a global biodiversity hotspot
2. Understanding of the influence of climate change as an evolutionary driver
3. The historic and palaeohistoric influence of man on speciation
4. The risks posed by climate change and habit loss on plant lineages

Training opportunities:
The student can work in all three institutions and get training offered in each one (e.g. phylogenetics and interpretation of climate models at UoR, GIS at IoZ)
The RHS publishing and RHS shows are known internationally in horticulture and offer a globally recognized platform for communication of all science linked to horticulture. The RHS science team is a unique multidisciplinary group dealing with the science of horticulture who communicate with ca.500000 members and through their website to a global public. It is expected the student will spend some of their CASE placement time with RHS outreach staff to develop skills in science journalism. There will be opportunities to visit field sites during the PhD through our extensive network of collaborators and through funding via the RHS bursary scheme.