About the project
Across all walks of life, from bacteria to plants and animals, there are examples of ‘mega-diverse’ genera, often sitting in groups containing other much smaller genera. What are the evolutionary causes and constraints behind this disparity in species numbers? This project investigates some key hypotheses.
The origin of new species represents a fundamental evolutionary process, with one lineage becoming two. In some species, the genomics of speciation have been investigated and key genes and processes implicated. However, we lack information on why the speciation rate differs between lineages.
In some groups, speciation is rapid, with many species originating in short periods of time, whereas in others this is slow. There are several examples where members of the same family differ in their number of species by >10-fold (e.g., in the Amaryllidaceae, Caryophyllaceae and Cyperaceae). Why are some lineages apparently prone to speciation and others not? The goal of this project is to investigate this from genomic and ecological angles.
We break this down into the following stages. We focus on the British flora, one of the best studied in the world:
- UK flora-wide, identify closely related genera which differ in number of species by >10-fold
- produce phylogenies to examine speciation rate and date the events, examining whether climate change and glaciation could have played a role
- working with herbarium samples and greenhouse-grown plants, examine changes in life history (e.g., annual or perennial), genome size, ploidy, and other phenotypes to determine whether rapid speciation is linked to these traits
- examine mutation rate, both across species, and from a mutation accumulation experiment to determine whether faster speciation is linked to faster mutation rate
You will learn wet lab skills, bioinformatics and experience working with herbarium material.
You will also be supervised by organisations other than the University of Southampton, including Chris Dixon and Dr Mark Carine from the Natural History Museum.
