PhD in water isotope zoology

The Institute of Geology, Mineralogy and Geophysics, Faculty of Geosciences, Ruhr-University Bochum, Germany, has a PhD position available.

We are inviting applications for PhD position (m/f/d) for 3.5 years (75% TV-L E13).

Application deadline: 29.07.2024

The Project: Living cells require water to function. Nevertheless, highly adapted specialists including insects are observed in the fierce water limited conditions within fog free zones of hyper-arid Deserts. The main research question addressed in this project is: Where do these organisms get their water from? Individual food and water sources comprise distinct oxygen and hydrogen isotopic compositions, that are reflected in body water isotopic composition (δ2H, δ17O and δ18O). Preliminary data for insects from the Atacama Desert shows a large isotopic range for darkling beetles and silverfish relatives. By comparing such measured isotope compositions to theoretical isotope models of the body water, it is possible to identify and quantify the water sources of these xerophilous insects. The preliminary dataset is to be extended, which requires field work in the Atacama Desert, Chile as well as the Namib, Namibia. In addition, laboratory experiments are planned both to improve the insect body water models, but also to explore if the concept can be applied to bacteria.

The position is funded by the German Research Foundation (Deutsche Forschungsgemeinschaft) within the framework of a Collaborative Research Centre (Sonderforschungsbereich SFB1211) entitled: "Earth - Evolution at the Dry Limit".

Responsibilities and requirements: The primary objective of this position is to quantify the water balance (both sources and sinks) of arthropods living in hyper-arid Deserts. This goal requires to improve our quantitative understanding of water isotope fractionation associated with sources (e.g. O2 from air) and also sinks (e.g. water loss through the cuticular). These mechanisms are already well explored for vertebrate models, but must be adapted to the physiology of insects. Detailed planning of respective laboratory experiments requires knowledge of both isotope fractionation mechanisms and Insect physiology. Thus, a background in Zoology or isotope geochemistry is desirable, but neither is mandatory. Some of the applied methods will be further improved within the framework of this project, which requires technical skills, ideally including programing. This project may well involve some unexpected setbacks, which will require a certain resilience towards project delays. We are thus seeking for a highly motivated candidate that is eager to explore this new research field. The successful candidate is expected to present results on national and international conferences, and to publish in peer-reviewed journals. For these tasks, demonstrated experience in scientific writing and communication in English is a must. The PhD candidate must hold a MSc degree or equivalent in natural sciences.

What we offer: The position is based at the Ruhr-University Bochum, Germany within the Faculty of Geosciences, but with a close collaboration with the University of Cologne. The Institute of Geology, Mineralogy and Geophysics at Bochum has an exceptionally good laboratory facility for isotope geochemistry. Besides a range of Mass spectrometers to perform the isotope analyses, the infrastructure is suitable to conduct most of the planned experiments. Some measurements and experiments will also be conducted at the University of Cologne as well as the University of Bonn.

Prof. Daniel Herwartz (Ruhr-University Bochum) has a long-standing focus on stable isotopes, while Prof. Reinhard Predel (University of Cologne) is an entomologist. Within the present project we offer the opportunity to work on a cross disciplinary project, where state of the art methods from geochemistry are applied to a classic challenge in biology. We aim to create ideal conditions for using these synergies for conducting high profile research within this young field of 'Isotope Zoology'. The position at the Ruhr-University, in the Institute of Geology, Mineralogy and Geophysics is available from 1.09.2024. A later starting date will shorten the duration of the project, which is up to 45 months. For details and further information, please contact Prof. Daniel Herwartz (

Interested applicants should email their application in pdf format to (cc to by 29.07.2024 at the latest.

Please provide a single pdf including:

  • 1-2-page cover letter outlining your academic background and skillset, the reasons you are interested in the project, and other points of relevance
  • CV and academic transcript (a copy of your M.Sc. degree certificate and any other relevant documents)
  • Contact details of one or two former advisors or supervisors (referees)

Once shortlisted, we will arrange for a videoconference or in-person interview.

posted: 01 July 2024     Please mention EARTHWORKS when responding to this advertisement.