Stories about evolution

Christophe Dessimoz, professor of bioinformatics at the University of Lausanne and University College London and group leader at the Swiss Institute of Bioinformatics (SIB) and his colleagues at SIB Marie-Claude Blatter, outreach manager, and Monique Zahn, training manager, have one thing in common: they are researchers who are passionate about evolution and about popularising science. More specifically: Christophe Dessimoz builds phylogenetic trees to study the relationships between living beings. Together, they wish to familiarise the public with this approach through the Agora project "In the Light of Evolution". They have been awarded this year’s Optimus Agora prize, which will be presented to them in September at the Agora Forum conference in Fribourg. 

Explain to us: what is a phylogenetic tree?

Christophe Dessimoz: It is a diagram that shows how different species have evolved in relation to their common ancestor. For example: humans compared to the gorilla or the mouse, but also compared to the fly, or the banana. Nowadays, phylogenetic trees are constructed from DNA or protein sequences using tools from bioinformatics.

In what way is this scientific approach useful for us today?

Christophe Dessimoz: Let's take a current example. This approach allows us to study the evolution of the coronavirus around the world and to identify its new variants. Phylogenetic trees have become essential for studying epidemics. Beyond the relationship between species and viruses, this approach can also be used to study the evolution of genes within species. This is very helpful in finding the most appropriate model organisms to study and better understand humans. And that's not all: cancers develop because of cells that proliferate uncontrollably. By reconstructing these progressions through phylogenetic trees, it is possible to better understand the molecular causes and in some cases to adapt treatments.

And how did the "In the Light of Evolution" project come about?

Christophe Dessimoz: We realised that evolution is a concept that is not well known among the public. At the educational level, the principles of Darwinian evolution are often not addressed until the upper secondary level. So a large part of the population has no idea how it works. But it enables us to answer a whole host of scientific and societal questions. Today, we have examples that allow us to approach it in a more down-to-earth manner.

Your project is designed to be fun. Is this essential for gaining the attention of the public?

Marie-Claude Blatter: Yes, we must not scare people! The playful aspect is a gateway to dialogue and from there on to scientific concepts. And these concepts are most easily understood if you experience them yourself.

Christophe Dessimoz: Having to arouse public interest is not unique to our field of research. As scientists, we have to explain why our work is interesting. What is different about evolution is that it is an abstract concept and therefore difficult to communicate. With this project, we want to make things as concrete as possible. 

What will you propose?

Christophe Dessimoz: The main point is to produce small stories, ten in total, spread over the three years of the project and showing what phylogenetic trees can be used for. For example: what are the similarities and differences between the sequence of a collagen protein in Tyrannosaurus and in chicken? How much DNA do humans and bananas share? These stories will be presented on a website and enhanced with multimedia or interactive elements such as quizzes.

Marie-Claude Blatter: In addition, one part will be small experiments that can be done at home using an ordinary pencil or a computer, or presented at a scientific event. One proposal might be to work with rulers showing DNA sequences from different species to find the most similar sequences and trace them back to a common ancestor. It will also be possible for teachers to train or host workshops in the classroom.

Monique Zahn: The story-based workshops will provide access to data and protocols to replicate the analyses performed by scientists. It's also a way of showing that science advances faster when you have access to data. And it will show how science works, how it fumbles before finding answers, but that this does not call into question the knowledge already acquired. This is very easy to show using evolution as an example.

How will you choose the stories?

Christophe Dessimoz: Each will be linked to a peer-reviewed publication. They will be based on work in which we are personally involved, or on the work of colleagues. The idea is really to make a link between research and popular science.

You also want to present the limitations of this scientific approach. Why?

Monique Zahn: Let's take the example of the origin of the coronavirus. To find it, we need to compare the sequences of the virus in different species. We can only make or break assumptions based on the available data. It is important that the public understand these limitations.