The Nonesuch lagerstätten: an insight into the origins of terrestrial biodiversity and the second carbon-cycle

Background

It is generally considered that life originated in the oceans some 3.5 billion-years-ago from where it diversified with all of the major evolutionary transitions taking place here: origin and diversification of prokaryotes, origins of sex, origin and diversification of eukaryotes, origins of multicellularity etc.

Life is believed to have been essentially excluded from the land surface for much of Earth history due to low oxygen levels and insufficient screening from UV-B radiation. Consequently, following the Cambrian Explosion, the oceans teemed with a bewildering diversity and complexity of animal and algal life - while the continents are considered to have been essentially barren.

We have discovered an extraordinarily rich and well preserved fossil biota from the billion-year-old Nonesuch Shale of Michigan, USA that challenges this assumption. The Nonesuch Shale is a very rare example of a terrestrial deposits that is one billion-years-old. It has yielded astonishingly well preserved fossils representing both prokaryotes and eukaryotes—including some that appear to be multicellular.

Aims and Methods

The aim of this project is to describe and analyse these fossils and use them to interpret the nature of the earliest terrestrial life on the Earth.

We have already collected a suite of samples and these will be supplement during fieldwork in Michigan directed by co-supervisor Professor Paul Strother (Boston College). The fossils will be prepared using acid maceration and analysed using light, scanning and transmission electron microscopy.

The aim is to document the diversity and shed light on the biological affinities of the fossils. Thus the earliest known terrestrial ecosystems can be reconstructed in terms of their biodiversity and ecology.

However, the project will also broach the thorny issue of whether all of the major evolutionary transitions in the history of life took place in the oceans. Is it possible that some of the major events in the early diversification of life took place on the land before migration into the oceans?

The student will also undertake analysis of sediment surface structures in order to ascertain the relationships between early life on land and sediment surfaces. This will employ novel techniques developed by co-supervisor Prof Paul Kenrick (Natural History Museum, London).

By understanding the relationship between early life on land and soil/sediment/rock surfaces, including contribution to biomass, we hope to be able to understand the contribution of these earliest terrestrial ecosystems to weathering, soil formation, biomass burial and hence the origins of the second carbon cycle on planet Earth: the terrestrial carbon-cycle.

Supervision and Training

The studentship will be based in Sheffield under the supervision of primary supervisor Prof Charles Wellman and utilise the unique facilities of the Centre for Palynology.

The student will visit the Natural History Museum, London to work with co-supervisor Prof Paul Kenrick on soil/sediment/rock interactions and Boston College, USA to work with co-supervisor Prof Paul Strother (and undertake fieldwork in Michigan).

The student will be trained in diverse palaeontological techniques with a view to pursuing a career in academia (biological or Earth sciences) or industry (eg biostratigrapher in the oil industry).

Science Graduate School

As a PhD student in one of the science departments at the University of Sheffield, you’ll be part of the Science Graduate School. You’ll get access to training opportunities designed to support your career development by helping you gain professional skills that are essential in all areas of science. You’ll be able to learn how to recognise good research and research behaviour, improve your communication abilities and experience the breadth of technologies that are used in academia, industry and many related careers. Visit https://www.sheffield.ac.uk/postgraduate/phd to learn more.

Eligibility

ACCE studentships are available to UK and EU applicants only.

Residency rules apply. UK and EU students with qualifying residence in the UK are eligible for full-cost awards. Non-UK students from the EU who do not have qualifying residence are eligible for fees-only awards, which covers the tuition fees and Research Training Support Grant (RTSG), but not stipend. 

Applicants are usually expected to be predicted or have achieved a first-class or strong upper second-class undergraduate degree (or equivalent international qualifications) in a relevant subject.

All applicants need to comply with the registered university's English-language requirements.

How to apply

Applications for the PhD are processed though the University of Sheffield's online application service.

• Please select ‘Standard PhD’ and the Name of the Department from which the title of the ACCE studentship is announced (ie Department of Animal and Plant Sciences).
• Fill in the Title of your desired project and the name(s) of the supervisors. (You can apply for more than one project to increase your chances to be nominated for an interview, but you can be interviewed for only one).
• As a ‘Study term’, - point out full-time or part-time PhDs depending on your wish.
• The starting date of PhD will be the start of the next academic year - 1 Oct 2020.
• ‘Funding stage‘ on the form will be ‘project studentship‘.

The deadline for applications is 8 January 2020.