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Dr. Essie Rodgers joins the lab!

Essie with her Ph.D. study organism! How cool would it have been to work on crocs?!

Fantastic news! Dr. Essie Rodgers has just moved to the ANU to join the lab. Essie is an ecophysiologist who comes from a long line of amazing physiology labs. She did a Ph.D. with Craig Franklin and Craig White at the University of Queensland before jumping continents for postdocs at the University of California at Davis (Fangue Lab), and then to Belgium at the University of Antwerp! Finally, she has come back home (to a colder part of home at least) to work on lizards, beetles and some very cool meta-analyses. Welcome, Essie!!

Looking for a Ph.D. student to join the lab

I’m looking to expand the lab group here at the ANU. If you’re interested in doing a Ph.D. with me in an amazing School check out the details below and get in touch!

The Project: The Noble lab (http://biology.anu.edu.au/people/daniel-noble) at the ANU is seeking expressions of interest from high-quality international or domestic candidates interested in pursuing a PhD exploring the links between metabolism, thermal plasticity and maternal effects in an Australian lizard. Field and lab experiments will be designed to test both predictions and assumptions stemming from pace-of-life theory and the metabolic theory of ecology. There is ample flexibility for the candidate to develop and pursue their own research questions within this grand theme, but there is an expectation that the candidate will make use of broad-scale meta-analytic and comparative approaches in combination with manipulative experiments.

The Candidate: Suitable applicants will be enthusiastic and highly motivated, with a strong academic and research background.  A demonstrated ability to conduct research is required and the student should have lab and field experience along with an interest in physiological processes. Experience in programming and data analysis is also desirable, but not essential. 

Location: The candidate will be based in the Division of Ecology and Evolution at the Research School of Biology at the Australian National University in Canberra, Australia. The ANU is one of the best universities in the world and is one of the highest ranked universities in Australia. The candidate will make use of ANU’s excellent semi-natural outdoor mesocosms and temperature controlled facilities for conducting experiments. Fieldwork will take place along Australia’s east coast. The candidate will also work closely with collaborators, both abroad, and within the Research School of Biology (http://biology.anu.edu.au/research/divisions/ecology-and-evolution) for various aspects of the project. 

Expression of interest: Expressions of interest should be submitted directly to Daniel Noble (daniel.noble@anu.edu.au)  by August 2, 2019. Please include a brief statement on why you are interested in this project, a CV and contact details for references. Following an assessment of applications, one applicant will then be invited to formally apply to the ANU. You can also find out more information about the graduate program by clicking on the “Higher Degree by Research” tab at http://biology.anu.edu.au/education/degree-programs.

Another bad day for anticipatory maternal effects

By Tobias Uller

A new study on water fleas, headed by Reinder and Alex, suggests that a classic example of adaptive maternal effects is not as adaptive as we might have thought.

Some years ago, Tobias, Sinead and Shinichi did a meta-analysis that seemed to undermine the idea that maternal effects are designed to transfer information about the local environment. Reviewers and editors did not really want to hear that, and the paper proved somewhat difficult to publish (but has been well received and cited). But one ‘anticipatory maternal effects’ appeared well supported: water fleas exposed to toxic cyanobacteria produced offspring that were more tolerant to the toxin.

So, to understand how this maternal effect evolves, Reinder and Alex challenged water flea mothers and offspring with cyanobacteria that produce the toxin microcystin. But rather than just expose the animals throughout their lives, they also exposed mothers at different times during her life. The rationale is that maternal effects that have been selected to transmit information are expected to behave like signals – triggered and delivered by a system well designed to pass on information with limited cost to the receiver.

It turned out that offspring indeed were somewhat better able to handle the toxin when their mothers had been exposed late in their lives. In other words, tolerance or resistance can be transmitted to the next generation through non-genetic means. But there was not much to suggest that the mechanism has been selected to transmit information about the presence of cyanobacteria. Instead, our experimental evidence – along with a meta-analysis of Daphnia research – fits better with a model of passive transfer of tolerance rather than an anticipatory maternal effect. Again, reviewers and editors were not very happy to hear this, and this paper also proved somewhat difficult to publish.

We should not be too surprised of these results, however. Not all plastic responses that allow organisms to cope with stress are properly seen as adaptations to cope with the stressor. We can think of these maternal effects as – in Mary-Jane West-Eberhard terms – examples of phenotypic accommodation that have not yet been followed by genetic accommodation.

But while our results question if there really has been selection for maternal transfer of information about microcystin exposure, the study is still not quite conclusive. Two kinds of follow-up studies would be particularly informative.

The first is to contrast responses of populations of water fleas with different evolutionary histories of exposure. This kind of comparison can effectively reveal if plastic responses in naïve animals become fine-tuned over evolutionary time (see a nice example from house finches here).

The second is to reveal the mechanism of the maternal effect. This would not only tell us ‘how it works’, but – keeping the comparison with signals in mind – whether or not the mechanism has properties that we expect of systems designed to transmit information.

We have our ideas about what is going on, and Alex has just completed a set of experiments that can tell us more. In the meantime, we hope that this paper will inspire more studies to look at maternal effects as a window into the evolutionary transition from stress-induced responses to local adaptation. To get started, please see here and here.