Evolution as a narrative in teaching biology

The lecturers of the Department of Biology at ETH Zurich are reorganizing their study programme to use evolution as the guiding principle of the Bachelor’s degree programme. Students beginning their biology studies this autumn will be confronted with the question of what the basic principles of life are and how life could have started on our planet about four billion years ago. On the one hand, the new approach focuses on the conditions that must be prevalent for life to emerge; in other words, how the environment may have enabled and shaped organisms. On the other hand, this approach also addresses the general question of what each cell has to accomplish in order to reproduce – not only in relation to Earth, but also, say, to another planet.

Specifically, the students begin by looking at the chemical virtuosity of relatively simple unicellular organisms such as bacteria and archaea. Only then do they move on to contend with the extremely complex regulatory processes that were necessary for the emergence of highly developed organisms such as plants, animals and humans – organisms distinguished by their huge numbers of differentiated cells.

Revealing connections

“By aligning our material to the history of organism development, we can focus more on highlighting general principles and interdependencies and less on teaching disconnected facts”, Julia Vorholt, Professor of Microbiology, explains the new orientation. Vorholt initiated the curriculum reform and heads up the project in the department.

Up to now, students at ETH began their biology studies by learning about plants and animals, following the traditional biology curricula one finds everywhere. “We wanted to move away from that,” Vorholt says, continuing: “If we start with complex multicellular organisms, we run the risk of obscuring the view of the overall biological context.” Biochemistry textbooks, for example, are often based on the metabolism of specialised cells, such as a human liver cell. “But other cell forms have other ways of obtaining energy or dividing themselves,” Vorholt explains.

Intuitive flow

It is not a coincidence that the impetus for the reform came from a microbiologist. Vorholt’s research looks at bacteria and archaea – the only two groups of organisms whose existence stretches back to the first half of Earth’s history. Although they laid the foundations for all life on our planet, they have so far only been covered until later in the degree programme. “This is not intuitive, especially when you consider that, according to current knowledge, we can trace all organisms back to a common origin,” she says.

Vorholt expressed her concerns about the then existing Bachelor’s degree programme at a biology department retreat, where she outlined her idea for a complete overhaul. Her proposal met with interest, followed by discussions that encouraged her to continue developing the concept with a group of colleagues. When Vorholt presented this concept to the department six months later, the main objection was that there was no textbook available off the shelf. “We have to be creative and collate the material ourselves,” was her reply.

Crafting a narrative

It was clear to all the lecturers that such a realignment meant quite some extra work. Yet the willingness was there and a curriculum group was set up with the mandate to redesign the Bachelor’s degree programme to the core. Besides professors and educational developers, the group included students as well.

The project group drafted the overarching storyline and a proposal for how to structure the curriculum. “In our courses, we can no longer present individual topics in isolation, but have to fit them into the context,” Vorholt says. To emphasise general concepts, it is necessary to consistently coordinate the study content. “It’s like a relay race; first we have to go from A to B, then from B to C, and so on,” she explains. The department approved the narrative and then decided who would teach which materials in which course, so as to take full advantage of the lecturers' expertise.

Reworking content

That was the starting signal for fleshing out the content of the courses. “In doing so, it’s important for the lecturers to work together and to identify and coordinate connecting points, so that the course materials build on each other,” Vorholt emphasises. The course material is stored centrally so that all the lecturers can incorporate previously presented material into their own courses. For example, reusing illustrations the students have already seen will reinforce what they have learnt.

It was not only the biology department’s professors who demonstrated a strong commitment to the reform; the same was true for lecturers from other departments, especially in chemistry, who give lectures for the biology students. “We have interlinked chemistry and biology in such a way that the relationship between the disciplines is clear right from the start,” Vorholt says.

Encouraging critical thinking

The result is an unprecedented concept for a Bachelor’s degree programme, which simultaneously pursues a further important goal. “Right at the outset we confront our students with big unresolved questions: How did life begin? And how did theories about life and its origin develop over time? In this way, we hope to incite student curiosity and stimulate their critical thinking skills,” Vorholt says.