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The Elephant's Trunk - and Other True Stories

Identifying and addressing the underlying causes behind misconceptions in biology



It is fair to say that most students of biology do not subscribe to the view that the elephant’s famous trunk is the result of a tug-of-war with a crocodile, as told in the children’s Just So Stories!


The trunk evolved, over time, by the process of natural selection. There are, however, a number of common misconceptions about evolution and other topics that are held among biology students, even biology majors. It is interesting to delve into what lies behind these misconceptions and to explore ways to address them, in order to gain insights as to how we might improve science communication.


A number of misconceptions are related to the theory of evolution, not least that it is ‘just a theory’, which arises from the distinction between the word ‘theory’ as it is used in everyday speech versus the scientific definition of a theory, which is a body of evidence supported by numerous observations and experiments. Another misconception around evolution is the idea that an organism ‘adapts itself’ to its environment. For example, it is not uncommon for a student to write something along the lines of: ‘As the ancestors of dolphins spent more time living near water, they adapted themselves to an aquatic lifestyle, grew flippers, and developed a blowhole on the top of their head’. The key misconception here is that the ancestral dolphins adapted themselves in some kind of directed way as if they were predicting the need for such features, which would afford them an advantage as they moved into their new, watery environment. Evolution, however, is a process which has no forward planning and no directed outcomes; some organisms are well-suited to their environment — they survive, reproduce, and pass their successful genes on to the next generation — but there is no foresight involved in this process.


The misconceptions I have described are examples of what educational psychologists refer to as ‘cognitive construals’ — the informal views of the world and phenomena that individuals hold, based on their own assumptions and particular ways of thinking. It is one of the challenges in biology education, and science communication more generally, to address these cognitive construals when they occur and be able to provide clear, rational explanations as to why these construals are not correct from a scientific perspective.

The cognitive psychologists John Coley and Kimberley Tanner identified three common underlying causes of misconceived cognitive construals: teleological thinking, essentialist thinking, and anthropocentric thinking, and examples of each of these are outlined below.


1. Teleological thinking


The first underlying cause of misconceived cognitive construals, known as teleological thinking, refers to our very human need for causal stories behind the observations we make of phenomena around us, based on an assumption of goals, purposes or functions. An example of teleological thinking is one of those described above, where a student assumed that a dolphin ancestor made a purposeful effort to change itself into a form more suited to a life aquatic. Another example would be that cheetahs ‘adapted themselves’ to run faster in order to catch their fast-moving prey, whereas what actually occurred was that natural variation in the cheetah population meant that those individuals who could run faster had an adaptive advantage, survived to reproduce, and passed on their advantageous genes to their offspring.

Cheetahs did not 'adapt themselves' to run faster. (Adam Bodley)

2. Essentialist thinking


The second type of common misconception is related to essentialist thinking — a set of assumptions that an individual may make about concepts, such as the idea that a particular feature of a system is solely responsible for defining its overall identity. An example of this would be the misconception that different cells in our body have different DNA whereas, in fact, all of our cells contain the same DNA, but not all of the same genes are activated in all of our different cells. Another example of essentialist thinking is the misconception that all plants are photosynthetic. This is not true. For example, Rafflesia, the plant which produces the largest flower in the world, is parasitic and therefore does not carry out photosynthesis to make its own food. In biology there are frequently exceptions to every ‘rule’, thus we need to find ways to move beyond the idea that systems or processes must be defined by a particular characteristic that most of them share.

The flower of the parasitic Rafflesia plant. (Deva Darshan/Unsplash)

3. Anthropocentric thinking


The third misconception occurs when biological phenomena are viewed through an anthropocentric, or human-centered lens, where we ascribe human values or characteristics to non-human subjects. A common anthropocentric misconception is that plants take in food from the soil via their roots. It is easy to see how underlying, anthropocentric reasons for this misconception may arise — we think that all organisms, including plants, must ‘eat’ food, and that they, therefore, must do this in a way similar to humans. We are also sold essential micronutrients that plants do need to take in from the soil, and which are often referred to as ‘plant food’, that we then give to our potted plants. In reality, plants take in the raw material for their food — carbon dioxide — from the air. This misconception can be addressed by asking why, if plants take in their food from the soil, are there not then enormous holes in the ground at the base of every tree in a park or garden?


 

My perspective