Discovery Trajectories: how Sara Magalhães made Evolutionary Biology into a career

Sara Magalhães is a full professor at the Faculty of Sciences of the University of Lisbon and a leading researcher in the field of evolutionary ecology. She is the scientific coordinator of the Centre for Ecology, Evolution and Environmental Changes (CE3C), where she also leads the research group on Evolution of Host-Parasite Interactions.

Sara Magalhães arrived in the field of Evolutionary Biology through the guidance of Margarida Matos, who was not even her professor in the undergraduate degree she was taking at the Faculty of Sciences of the University of Lisbon (Ciências ULisboa), but who would come to influence the career that followed. Even today, the eyes of the current coordinator of the Centre for Ecology, Evolution and Environmental Changes (CE3C) reveal a special fondness when she remembers the moment of revelation of the then student in the 1990s.

“Professor Margarida Matos carried out laboratory research and I found all of that fascinating. And I also found fascinating Margarida Matos’s own enthusiasm about the subject,” says the coordinator of CE3C. “A large part of my research is related to interactions between organisms. The study of these interactions lies at the interface between ecology and evolution, because the behaviour of individuals as well as their abundance are affected by these interactions, which creates new selection pressures that alter the evolutionary trajectories of species,” adds the professor from the Department of Biology of Ciências ULisboa.

“Over generations there are different alleles (variants of one or more genes) that increase or decrease in frequency and these alleles can be associated with a trait. Let us imagine that this trait is beneficial, that is, that it leads organisms to have more offspring. If this trait is hereditary, the offspring of those organisms will also have this trait and, therefore, this trait will increase in frequency over time,” says the researcher about behavioural changes that occur through evolutionary processes.

Still during her bachelor’s degree, Sara Magalhães begins a period under the Erasmus programme at the University of Toulouse, in France. After this first contact abroad, she learns, through a friend, about the work being carried out at the University of Amsterdam, in the Netherlands, and it is there that she completes her PhD, in 2004, with a thesis entitled “To eat and not to be eaten: do plant-inhabiting arthropods tune their behaviour to predation risk?”.

“In my PhD, I studied several species. I studied predatory mites, but also thrips that are crop pests, among other species. Essentially, I was studying an entire community. Then came the postdoc at the University of Montpellier and I focused the study on (mites) Tetranychus urticae. Later, there was a period when I worked with bacteria and with (the worm) C. elegans, and then I went back to working with mites and, in parallel, with flies such as Drosophila melanogaster, and fly parasites, among other things,” the researcher sums up.

It was in 2006 that Sara Magalhães decided to leave Montpellier and return to Portugal – but she did not want to abandon the study of experimental evolution… given that “in Portugal, there was no one working on laboratory experimentation with mites.”

Faced with this situation, the theme remained the same, but with different species. And so, she spent two years doing research at the Instituto Gulbenkian de Ciência (IGC). “It was C. elegans or bacteria; that’s what there was,” recalls with good humour the researcher who is also the current coordinator of CE3C. “In those two cases I studied resistance both to nematicides and to antibiotics,” she adds.

Coming to the IGC fulfilled an initial objective – but Sara Magalhães still had two more “returns” to make: in 2008, she joined Ciências ULisboa and began her research career at CE3C. And mites quickly took, once again, the leading role in the research storyline.

“At that time, I began to establish a system with mites. At the same time, I was collaborating, in the study of flies, with Élio Sucena, who at this moment is my office mate. We studied the evolution of resistance to viruses and bacteria,” the researcher notes.

In the study of mites, the species Tetranychus urticae, T. ludeni and T. evansi stood out, which would be the subject of study up to the present day. In 2011, there was a first media moment, with the publication of a scientific article in the prestigious journal Science. In that study, Sara Magalhães and her collaborators reveal how mite communities evolve depending on the number of females available for reproduction. The study showed that mite populations that evolved in subdivided environments produced more daughters than sons, which allowed the colonization of new sites, whereas undivided populations produced an equal number of sons and daughters.

“Then, I began to study competition between mite species. That was the theme of the grant I won from the European Research Council (ERC) in 2017,” emphasizes the coordinator of CE3C.

With the title “COMPCON - Competition and niche construction”, the project supported by the ERC again had as main characters members of the species Tetranychus urticae and Tetranychus evansi, but it also included a tomato plant as a third element, forming a triangle of interactions. Tetranychus urticae and Tetranychus evansi are known for feeding on tomato leaves, but the first mite species leads tomato plants to increase their defences, while the second induces a reduction of those defences.

“The suppression of plant defences is beneficial for mites of the species Tetranychus evansi, but it is also beneficial for mites of the competing species (Tetranychus urticae). We studied the evolution of this triangle and how it affected interactions between species. And we found that, when the two species evolve together, Tetranychus evansi suppresses tomato defences less,” describes Sara Magalhães.

From interactions between species to interactions with other areas of knowledge was just a small step. With the ERC-supported project already completed, Sara Magalhães heads to the Institute for Advanced Study in Berlin, Germany, to join a reflection group with specialists from various fields of knowledge.

During her stay in the German capital, she wrote an article in partnership with a researcher in the area of Philosophy and a researcher in the area of Mathematics. Sara Magalhães admits that the study begun there left some chapters open that still have to be completed, but she did not consider the time wasted.

“I also tried to develop a little bit my project, which consisted of trying to understand what different interactions in the animal world (competition, predation, interaction between males and females) have in common, in terms of causes and consequences, so we can better study each of these interactions,” she explains. “The people who go to the Institute for Advanced Study in Berlin are interested in dialogue. If you’re typically that person who only does their science, you will never apply to this institute. So, when I was there, I found special people who were eager for dialogue. In that sense it was super interesting,” she adds.

“My goal is to strengthen the internal cohesion of CE3C. We are a spectacular centre; the coordinators who preceded me did a wonderful job and I don’t have any major problems. I want to continue their work and strengthen international visibility."

The act of returning is already part of Sara Magalhães’ résumé – and it is no longer surprising that, in 2025, she came back to CE3C. Only this time, the researcher also came to embody the role of coordinator of CE3C. Sara Magalhães does not hide that she has always felt more inclined toward scientific and laboratory research than toward the application of scientific knowledge in the development of products or services, but she also knows that the challenge is to bring out the best in each researcher.

“My goal is to strengthen the internal cohesion of CE3C. We are a spectacular centre; the coordinators who preceded me did a wonderful job and I don’t have any major problems. I want to continue their work and strengthen international visibility. We have several people who are internationally known, but the Centre itself still needs to make a ‘name’ for itself. I would also like CE3C to be more sought after when it comes to public issues and policies, so that we can have a greater role in our areas of knowledge,” she says. Evolution is the way forward.