Climate and amphibians

In the coming decades we might face the loss of more than 50% of the climatic ranges for more than half of plants and 34% of animals [1]. Abrupt greenhouse‐driven climate change and synergistic effects, e.g. disrupted migration pathways and breeding cycles, changing predator, competitor and prey relations, habitat‐loss as well as diseases, are significant contributors to this biodiversity destruction. Although often ignored from a public perspective, or considered to be of lesser importance than likeable flagship species, amphibians alongside reptiles might face greatest extinction risk under current changing climate [2].

This project aims at connecting changing climatic conditions and temporal trends in amphibian traits, including extinction risk and diversity, to expand our knowledge about current and future extinction threats to amphibians. The project uses oxygen isotope data to reconstruct the relative temperature changes as well as latitudinal temperature gradients.

  1. Warren, R., et al. “Quantifying the benefit of early climate change mitigation in avoiding biodiversity loss.” Nature Climate Change 3.7 (2013): 678‐682.
  2. Stuart, S. N., et al. “Status and trends of amphibian declines and extinctions worldwide.” Science 306.5702 (2004): 1783‐1786.

Extinction risk in fossil and living amphibians


Amphibians are the most endangered terrestrial vertebrate group [1]. Several studies examined biological as well as environmental and also anthropogenic factors, that can potentially add to extinction risk [2]. Typical influential factors are the geographic range size and bodysize of a species, which have been confirmed in studies on fossils from extinct species as well [3].

Although amphibians are one of the most threatened groups today, their fossil record and therefore the past of amphibians is rarely taken into account. As the fossil record invites to study plenty of real extinction events, it is assumed that it can give valuable information about factors influencing a species survival.

Beelzebufo ampinga by Nobu Tamura ( (Own work). GFDL or CC BY 3.0, via Wikimedia Commons

My work

Part of this project is to test the potential of combining the amphibien fossil record with neontological data. I am creating a paleontologically calibrated model, which is based on the fossil record of amphibians and predicts the species duration with certain traits like geographic range size, body size, and other factors that might be of importance for extinction risk. This fossil-calibrated model is then applied to living amphibians and use to predict a hypothetical duration for those species, based on their traits. The predicted extinction risk is compared with the risk category the species has been assigned to by the IUCN Red List assessment.

First results have shown that the predicted durations for living amphibian species are on average inversly correlated with the extinction risk as it was assigned to the species by it`s IUCN Red List assessment.


  1. Baillie, J. E. M., Griffiths, J., Turvey, S. T., Loh, J. & Collen, B. 2010 Evolution Lost: Status and Trends of the World’s Vertebrates. Zoological Society of London.
  2. Sodhi, N. S., Bickford, D., Diesmos, A. C., Lee, T. M., Koh, L. P., Brook, B. W., Sekercioglu, C. H. & Bradshaw, C. J. A. 2008 Measuring the meltdown: drivers of global amphibian extinction and decline. PLoS One 3, e1636. (doi:10.1371/journal.pone.0001636)
  3. Harnik, P. G. 2011 Direct and indirect effects of biological factors on extinction risk in fossil bivalves. Proc. Natl. Acad. Sci. U. S. A. 108, 13594–13599. (doi:10.1073/pnas.1100572108)

Fellow Program Open Science

Besides bridging the gap between the fossil record and current biology in my PhD work, I am interested in different concepts of Open Science. This website was initialized as part of my work as a fellow in the Open Science Fellow Program. Launched for the first time in 2016 by Wikimedia Germany and Stifterverband the fellow program enables 10 scientists from different areas to open up their research by providing guidance and financial support.

I created this website as part of my work in the Open Science Fellow Program. Open Science needs communication, and what better way could there be than making your science explorable online? While learning to use GitHub, I stumbled across GitHub Pages, which resulted in this webpage.

As part of my project in the fellow program, I concentrate of the aspects reproducibility, community feedback and open publishing. If you are looking for inspiration on how you can make your own research more open, the Vienna Principles offer some ideas.

Video summary of the project (German):


Making your research reproducible is part of good scientific practice. Therefore, I want to publish the R scripts used in my analysis together with the data and the manuscript. This can be part of the electronic supplement but can also be hosted independently on GitHub.

Community feedback

Getting feedback on your work when it comes to peer review is good, but getting feedback even earlier, while it is still in progress, might speed up the whole process. Reaching out to your research community gets you valuable tips on your work. However, this costs time (as building this webpage for example). Therefore a part of my project is the evaluation of opening up your research in terms of costs and benefits.

Open publishing and preprints

Publishing my work in an open access journal will be the last milestone in this project, but before that I plan on something way more interesting. I want to test preprint and preprint servers, which is something that, for biology or paleontology, is sparsely used in my surroundings. Finding the right preprint server to adress the right crowd as well as responding to hopefully plenty of feedback will be valuable experiences and will likely add to quality and make the publication process a bit easier in the end.

Another option in the peer review process is aiming at a journal that offers open peer review, which is getting more and more common and adds to the transparency in the review process.

This page is licensed Creative Commons License

2018 Melanie Tietje
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