The Mason Hale Award is granted to recognise excellence in research by young lichenologists for outstanding work resulting from doctoral dissertations or similar studies, and the IAL awards one Hale Award each time. As usual, the Hale Award Committee had an unusually difficult task, with a large number of exceptionally good PhD thesis nominations to consider. Every nomination could easily have been a worthy recipient.
The Mason Hale Award 2016 is given to Fernando Fernández-Mendoza for his thesis “Genetic diversity and gene flow between Arctic and Antarctic populations of the lichen Cetraria aculeata along the Andes and the Rocky Mountains,” which he produced at the Johann Wolfgang Goethe-University in Frankfurt am Main, Germany, primarily under the supervision of Christian Printzen.
Fernando’s thesis is one of the very first modern studies on the classical biogeographical problem of the origin of bipolar lichen distributions, taking into account the complexity of multi-partner symbiosis (including the constantly occuring bacteria), factors influencing biogeographical patterns, and basic population genetic mechanisms to explain observed patterns of genetic diversity in lichens.
In his thesis, Fernando focuses on how and when the disjunct distribution of Cetraria aculeata originated, and what roles different historical and ecological processes played in shaping this distribution. One example is that he shows that photobiont presence is partly a response to a selective process related to climate. This climatic pattern is also found in the bacterial community in C. aculeata. Lichen fungi may, therefore, be able to respond to different environmental conditions by selectively associating with different symbiotic partners.
Fernando’s studies reach beyond both lichenology and the study of symbiotic organisms. There are several examples, but I will mention one. When struggling with the problem of dating historical dispersal events in populations, when haplotypes are widely distributed geographically, Fernando treated dispersal events as character state transitions among geographical regions, and developed a new method to model the evolution of geographic ranges along phylogenetic trees, making a time-explicit use of stochastic character mapping.
The very novel idea here is that he focused on identifying the relative dates of the dispersal events and their distribution along tree time, using ultrametric phylogenies. This allowed him to show the following: Cetraria aculeata dispersed from the Northern Hemisphere into South America during the Pleistocene; that Patagonian populations became isolated earlier than the more northerly Bolivian populations; and that Antarctica was colonized from Patagonia as recently as 50-100k years ago.
Fernando’s dissertation is highly innovative, and contains conceptual and methodological advances where problems are studied in an integrative way, using a wide range of approaches and perspectives. His work is pioneering for future biogeographical studies, and he is a most worthy candidate for the Mason Hale Award!
On behalf of the Committee and the IAL Council, I congratulate Fernando, and wish him all the best for his future career!
– Mats Wedin, Chair of the Hale Award Committee, Stockholm (Sweden)