Branching Out: what fossils, ferns and genes reveal about the evolution of shoot branching architecture in plants

About the project

About the Project Today, plants display a rich diversity of shoot architectures, underpinned by a range of branching types. But this was not always the case. During the early stages of plant evolution branching was restricted to a single primary type, termed dichotomous branching. This all changed during the Devonian and Carboniferous when a revolution in branching occurred. By 300 million years ago a suite of new branching forms had evolved in the major groups of vascular plants including lateral and axillary branching and these branching forms underpin modern shoot architecture. Despite this being a critical time for plant evolution, the precise evolutionary and developmental steps that facilitated this expansion in branch types remains unclear. In this PhD you will take an interdisciplinary, “Molecular Palaeobotany” approach to shed new light on branch evolution. In the project you will combine three distinct but interlinked lines of evidence: Fossils: You will interrogate the early fossil record of branching to define more clearly the diversity of branching types present and when key branching type evolved. This work will utilise fossil collections held in the Molecular Palaeobotany and Evolution Group at the University of Edinburgh and in National Museums Scotland. Ferns: The three major groups of vascular plants today, lycophytes, ferns and seed plants each possess characteristically different modes of branching. Lycophytes branch dichotomously, seed plants are characterised by almost exclusive axillary branching – but ferns possess a mixture of the two. Ferns provide an ideal system to study branching evolution and development. You will characterise branching types in living ferns by sampling the rich diversity of ferns at Royal Botanic Gardens Edinburgh, supported by Dr Michael Sundue a member of the supervision team. Genes: Ferns provide examples of closely related species with distinct modes of branching. They provide an excellent system to investigate how gene expression varies between different types of branching. You will investigate gene expression in ferns and be supported in this with expertise within the supervision team from Dr Annis Richardson (University of Edinburgh), and Prof Jill Harrison (University of Bristol. By the end of this interdisciplinary PhD you will have made a major step forward in our understanding of branching evolution in land plants, as well as equipping yourself with a diverse skillset to study major questions in plant evolution. The candidate: We seek applicants with a passion plant evolution, a drive to tackle major evolutionary questions and an enthusiasm to work in an interdisciplinary environment. We welcome applicants from a variety of backgrounds aligned with the study of evolution, evo-devo or palaeontology. The project dimensions: The position is based in the Molecular Palaeobotany and Evolution Group ( https://www.ed.ac.uk/biology/groups/hetherington ) run by Dr Sandy Hetherington, at the Institute of Molecular Plant Sciences, University of Edinburgh. How to apply: To apply please send a short cover letter, no more than 2 pages, and a CV to Dr Sandy Hetherington, sandy.hetherington@ed.ac.uk

Research areas