About the Project: Spirally arranged organs are incredibly widespread in plants and you may be used to seeing them in leaves, flowers and pine cones. What’s amazing about these spirals is that when quantified we find that they are almost always described by integers of the famous mathematical series – the Fibonacci series. In fact, in living species today >90% of botanical spirals are Fibonacci spirals.

Why Fibonacci spirals are so common in plants today has perplexed scientists for centuries, and remains a major unanswered question. In this PhD you will take us a major step closer to understanding why they are so common by uncovering their origin and evolutionary history.

This approach is motivated by our recent demonstration that non-Fibonacci spirals, that are rare in species today, were present in the earliest group of leafy plants, This finding suggests that the distribution of Fibonacci spirals has changed through time and we now hypothesise that there were times in the geological past when Fibonacci spirals were less common than they are today. A question you will specifically address in this PhD.

Combining together studies of fossils and living plants you will characterise the diversity of botanical spirals found in plants over 400 million years. This will require a combined approach making use of new techniques to quantify phyllotaxis, X-ray micro-computed tomography (μCT), analysis of fossils, comparative histology of living species and evolutionary approaches to predict character evolution through time.

Student requirements

We are looking for a student with a passion for plant evolution. The PhD is open to students with either a background in biology or geosciences and there is no need to have experience of investigating fossils.

The lab

The Molecular Palaeobotany and Evolution Group (https://www.ed.ac.uk/biology/groups/hetherington) led by Dr Sandy Hetherington specialises in tackling major questions in plant evolution using interdisciplinary approaches to study fossils and living plants.



The School of Biological Sciences is committed to Equality & Diversity: https://www.ed.ac.uk/biology/equality-and-diversity

How to Apply

The “Institution Website” button will take you to our online Application Checklist. From here you can formally apply online. This checklist also provides a link to EASTBIO – how to apply web page. You must follow the Application Checklist and EASTBIO guidance carefully, in particular ensuring you complete all the EASTBIO requirements, and use /upload relevant EASTBIO forms to your online application.

Funding Notes

This 4 year PhD project is part of a competition funded by EASTBIO BBSRC Doctoral Training Partnership View Website  This opportunity is open to UK and International students and provides funding to cover stipend at UKRI standard rate £18,622 annually in 2023) and UK level tuition fees.

The fee difference will be covered by the University of Edinburgh for successful international applicants, however any Visa or Health Insurance costs are not covered. UKRI eligibility guidance: View Website
Terms and Conditions: View Website


Key references
Turner HA, Humpage M, Kerp H, Hetherington AJ. 2023. Leaves and sporangia developed in rare non-Fibonacci spirals in early leafy plants. Science. 380: 1188-1192. DOI: https://doi.org/10.1126/science.adg4014
Reinhardt D, Gola EM. 2022. Law and order in plants–the origin and functional relevance of phyllotaxis. Trends in Plant Science. DOI: https://doi.org/10.1016/j.tplants.2022.04.005

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