PhD Studentship in tardigrade evolution at the Jagiellonian University (Kraków, Poland, EU)

 

Project

The nineteenth century naturalists were disappointed when they found familiar microbes instead of exotic species they had expected in samples from newly explored regions of the Earth. The conclusion seemed obvious – there are no microbe counterparts to kangaroos limited to Australasia or penguins to the southern hemisphere. This led twentieth century biologists to formulate the “everything is everywhere, but environment selects” hypothesis (‘EiE’). In short, the hypothesis states that microorganisms are free to disperse around the globe and they can thrive wherever environmental conditions are favourable. In the twenty first century, the hypothesis was extended to protists and to multicellular organisms that produce microscopic propagules or are themselves microscopic, i.e. no more than around 2 mm in size. The ‘EiE’ hypothesis bears important consequences for the evolution and biodiversity of microfauna, yet it has been tested on animals only once and the test was limited to showing that some rotifer species exhibit cosmopolitan distributions, whereas other do not. In other words, the results showed that the ‘EiE’ hypothesis does not explain why two species of a similar size may differ in their geographic ranges. Thus, other factors – environmental, species-specific or both – must be also taken into account to explain biodiversity patterns of microscopic animals.

Therefore, this project will utilise replicated models and various analytical tools to test, for the first time, the ‘EiE’ hypothesis in relation to environmental variables as well as species traits that are likely to affect dispersal potential of microscopic animals, i.e. reproductive mode and cryptobiotic survival (an ability to enter a dormant state that allows to withstand unfavourable environmental conditions). To achieve this, we are using two groups of limnoterrestrial tardigrades, microscopic animals that exhibit both sexual and asexual reproductive modes and varying degrees of cryptobiotic tolerance. These characteristics make tardigrades well suited for testing the hypotheses described below. Thanks to the robust sampling design (nine sampling regions on three continents, with replicated climate types) and well-resolved phylogenies (based on multilocus DNA sequences), combined with detailed data on reproductive mode and cryptobiotic survival, we will accomplish the two main objectives of the project:

(1) Test the ‘EiE’ hypothesis using tardigrades as model groups, i.e. test whether species are cosmopolitan or restricted by geography or/and environment. Given that tardigrades are smaller than 2 mm, at least some species should be cosmopolitan or limited to specific environments, but not restricted by geography.

(2) Test how reproductive mode and cryptobiotic survival interact in shaping species dispersal. The prediction is that both asexual reproduction and cryptobiotic survival should increase dispersal potential.

The data collected to test the main hypotheses will facilitate two additional objectives that, together with the ‘EiE’ hypothesis test, will add to our understanding of the mechanisms shaping biodiversity at local and global scales. These two further objectives address key themes of evolutionary biology – speciation and the evolution of sex. By analysing the phylogenetic trees, we will test how reproductive mode and dispersal affect:

(3) Speciation rates. Speciation rate of a lineage may be affected by both its reproductive mode (generally, theory predicts that sexual linages should diverge faster than asexual ones) and dispersal potential (which determines its chances to colonise new habitats).

(4) Lineage extinction risk. Similarly to speciation rate, the probability of lineage extinction may be affected by both its reproductive mode (generally, theory predicts that sexual lineages should be more persistent) and dispersal potential (extinction risk may also be mediated by dispersal as the more locations and habitats are colonised, the greater the chances of survival of the lineage).

Finally, the data will also allow two side objectives, related to biodiversity research and tardigrade taxonomy, to be completed:

(5) Reconstruction of phylogenies of the model groups. The use of multiple markers will allow reliable reconstructions of the relationships, possibly revealing evolutionary lineages within Tardigrada.

(6) Integrative descriptions of new taxa that most likely will be found while investigating the main hypotheses. These discoveries will enrich the knowledge on tardigrade biodiversity, especially in poorly sampled regions of the world.

The successful candidate will be involved in fieldwork (sample collection), sample extraction, slide preparation, morphometrics and imaging in light microscope, processing specimens for scanning electron microscope, karyotyping, DNA extraction, amplification and multilocus sequencing (NGS), species identification, and taking care of tardigrade cultures. The student will also analyse data and prepare drafts of manuscripts, and will be involved in the promotion of results at seminars and conferences.

Therefore, the offered PhD studentship presents a great opportunity to research the underlying mechanisms behind the evolution of biodiversity of microscopic organisms and key evolutionary phenomena such as evolution of sex and speciation. Although this is the central project aim, the system provides great potential for a dedicated student to explore other topical tardigrade biology and evolutionary questions that are under active research in our team.

 

Supervisor

Dr. Łukasz Michalczyk is an evolutionary biologist who happens to love tardigrades. He did his MSc at the Jagiellonian University (Kraków, Poland), then a PhD (2009) and a PostDoc at the University of East Anglia (Norwich, UK), followed by a Fellowship at the University of Western Australia (Perth, Australia). Currently, he holds a permanent position of an Associate Professor at the Jagiellonian, where he leads a dynamically developing group of young researchers. He published over a hundred research papers in international journals, including top periodicals such as Science and Nature (GoogleScholar profile). He has also been a Principal Investigator in projects concerning some of the key areas of evolutionary biology inquiry such as sexual selection, inbreeding, phenotypic plasticity, and phylogeny.

 

Team

Our team currently comprises seven members: a wonderful Lab Manager (Magda), three talented PhD students (Daniel, Piotrek and Witek) working on various aspects of tardigrade biology, and three dedicated undergraduate students (Bartek, Łukasz and Kasia) who help the PhD students with their projects (team on ResearchGate). All PhD students already have a track records of research papers and numerous stipends. Next year we plan to hire a PostDoc and a few new undergraduates.

 

Lab

Our lab is located in the new building of the Institute of Zoology and Biomedical Research (part of the Faculty of Biology). The lab is fully equipped with the state-of-the-art equipment, including high class phase and differential interference contrast microscope, a number of stereomicroscopes, DNA lab, and incubators for tardigrade culturing. There is an SEM lab and DNA sequencing facilities on the campus (both Sanger and NGS). Our lab has the largest collection of tardigrade strains in the world. Our Institute also owns a Mountain Station in the Gorce Mts., where we go every summer and winter for a short seminar and team integration.

 

University

Jagiellonian University, founded in 1364, not only is the oldest Polish University but it is also one of the oldest universities in the world. Together with the Warsaw University, it is ranked as the top university in Poland. Our Institute is located in the new university campus in the Ruczaj district, which is surrounded by meadows and lies in the vicinity of the Vistula river. The campus is conveniently communicated with the city centre (20 min by tram). Famous Jagiellonian alumni include the astronomer Nicolaus Copernicus and Nobel Laureate Wisława Szymborska.

 

City

Kraków is one of the oldest Polish cities and it is also considered as one of the most beautiful in the country. With nearly 200 000 students studying at 20 universities and academies, it is a vibrant place with many pubs, clubs and other student attractions. Kraków is located in the south of Poland, thus gorgeous Tatra Mts., Pieniny Mts., Gorce Mts., and other mountain ranges are only two hours away by coach.

 

PhD programme

The PhD programme in Biology is run entirely in English and it includes some obligatory and facultative classes. The programme is open to all nationalities and there are no tuition fees. The PhD studentship will take four years: it will commence on the 1st October 2018 and the student is required to submit the PhD thesis by the 30th September 2022. The viva should take place by the end of 2022. The PhD thesis is planned to be in a form of a series of 3–5 research papers published in high rank journals.

 

Scholarship

The guaranteed tax-free stipend is 4 000 PLN/month for the duration of four years. Additionally, top PhD students receive extra up to 3 000 PLN/month. Thus, if you are an active and hardworking PhD student, you may earn up to 7 000 PLN/month (ca. 1 650 EUR or 1 450 GBP or 2 000 USD). If you choose to lead a typical PhD student life in Kraków, you will spend ca. 2 500 PLN/month, thus the guaranteed stipend assures a good standard of life and allows to save some money for the future.

 

Requirements

Formal: An MSc diploma (or an equivalent that allows to enter a PhD course) in biology or in a related field, already in possession or to be obtained no later than on the 20th July 2018.

Personal: I am looking for an enthusiastic, motivated and hardworking person who is not afraid to learn new things and skills, someone who gets along with people and is happy to work in a team but is also able to operate independently, without a constant supervision. A strong interest in evolutionary biology, with emphasis on phylogeny, biogeography and taxonomy is a must, as is fluency in English (especially in writing) and fondness for tardigrades. Interest in bioinformatics is strongly advantageous. Experience with handling and culturing microscopic animals is desirable.

 

Recruitment procedure

The recruitment procedure is a two-step process. In the first step, 1–2 candidates will be preselected and then they will be given the opportunity to apply for a PhD position at the Jagiellonian University. The best candidate will obtain the PhD position.

Step I: To enter the first step of the recruitment, please download the Application Form, fill it, and send it with all specified information and attachments to LM@tardigrada.net by the 20th May 2018 (please try to apply as soon as possible rather than wait until the deadline – this will help us to select candidates for project interviews). Based on applications and references, several top candidates will be chosen for project interviews. These interviews will take place in early June 2018 (Skype interviews for international candidates are possible). You must pass this first step to be eligible to apply for the second step of recruitment (described below).

Step II: One or two best candidates selected in the first step will be then given help and advice to prepare for the official university entrance interviews. Detailed information about the university recruitment procedure may be found on the Faculty of Biology website (project no. IZBR-8). Information on the recruitment criteria and required documents is available in the Online Application System. The applications must be submitted by the 4th July 2018. University interviews will take place on the 16th July 2018 (Skype interviews for international candidates are possible). University interviews focus on the project and related topics. A track record of published scientific papers and documented experience in research projects extremely increase the chances of obtaining the PhD position.

 


 

If you know anyone who might be interested in this position, please send them the link to this website: http://tardigrada.edu.pl/PhD.htm
Thank you! :-)