Two PhD positions in Organic Geochemistry, Isotope Geochemistry and Paleontology

MARUM - Center for Marine Environmental Sciences at the University of Bremen invites applications for two four-year PhD positions within the ERC Starting Grant project " Deconvolving the early record of eukaryotic evolution. "

The project investigates how life and environments coevolved during the Neoproterozoic and early Palaeozoic, a critical interval in Earth history when eukaryotes became ecologically successful and animals emerged and diversified. It develops and applies molecular and isotope-based approaches in organic geochemistry and palaeontology to reconstruct ancient ecosystems, carbon-cycle dynamics and major environmental perturbations.

PhD Project 1: Carbon-isotope excursions in the Neoproterozoic and early Palaeozoic

This project will investigate major stable carbon-isotope excursions and the interactions between biological and environmental processes during these events. The research will combine biomarker distributions, compound-specific carbon-isotope analyses and broader geochemical and sedimentological records to constrain the nature, timing and drivers of major perturbations to the ancient carbon cycle.

Reference number: A129-26

PhD Project 2: The rise of eukaryote-dominated marine ecosystems

This project will explore ecological and evolutionary change from the early diversification of eukaryotes to the emergence of animal-dominated ecosystems. It will investigate how the composition of primary producers and the functioning of marine ecosystems changed through time, and how these changes are recorded by sedimentary biomarkers, fossils and stable carbon-isotope records.

Reference number: A138-26

Candidate profile

Applicants should hold, or be close to completing, a Master's degree or equivalent in Earth sciences, biology, chemistry or a closely related discipline. The Master's degree must be completed before employment begins.

Applicants should have:

• a strong interest in Earth history and interdisciplinary research at the interface of geochemistry, biology, geology and palaeontology;
• excellent written and spoken English;
• the ability to undertake international fieldwork and research travel;
• the ability to work both independently and collaboratively in an international research environment.

Previous experience in organic geochemistry, isotope geochemistry and/or Precambrian research would be advantageous but is not essential.

Salary and starting date

Both positions are funded for four years at 75% of German public-sector salary grade TV-L E13, a standard employment level for doctoral researchers in Germany. The preferred starting date is as soon as possible, with some flexibility.

Application

Applications should include:

• a cover letter;
• a curriculum vitae;
• copies of academic transcripts and degree certificates;
• contact details for two academic referees.

Please submit the complete application as a single PDF file , quoting the relevant reference number:

Project 1 - A129-26: [email protected]

Project 2 - A138-26: [email protected]

Applicants interested in both projects should submit separate applications quoting the respective reference numbers.

The application deadline is 18 August 2026.

Further details are available at:

For scientific or procedural questions, please contact the pricinipal supervisor for both projects: Dr Ilya Bobrovskiy [email protected]

Research environment and employment

MARUM is an internationally recognised centre for marine environmental research with a strong focus on the geosciences. Doctoral researchers benefit from an international research environment, a large network of PhD students and the training programme offered by the MARUM Research Academy.

The University of Bremen is family-friendly, diverse and international, and welcomes applications regardless of gender, nationality, ethnic or social origin, religion or belief, disability, age, sexual orientation or identity. Women are expressly encouraged to apply, and applicants with disabilities will receive preferential consideration where qualifications are substantially equivalent.