Ideas in this blog post eventually developed into a much more advanced idea presented in my book.
Life exists within the context of its interactions with the environment, it does not exist in a vacuum. Developmental plasticity, homeostatic mechanisms, and natural selection, all occur due to an organism, or a population, continually interacting with the biotic and abiotic factors surrounding them. In a similar vein to Dobzhansky’s famous words ‘Nothing in biology makes sense, except in the light of evolution’, neither evolutionary nor systemic (physiological) explanations make sense except in the light of their environment. But how often do biology curricula fully contextualise phenomena in their environment as an explicit central feature? How often do biology curricula isolate a concept from larger scales of organisation?
Recently I have been ruminating over a more contextualised curriculum, in which abstract ideas become more accessible and interesting to students. Nothing in biology is more contextual than the organism in its environment. After all, this is how most people experience nature. However, I also envisage a curriculum for changing students’ conceptual view of the world, one that instills a particular biologist’s gaze based on big questions and big ideas. A heuristic for approaching new contexts of life, new organisms in new environments.
Image by Christian Moore Anderson & Blanca Martínez Valiente
Generalisations to new contexts must come from a sound knowledge of specific examples of similar organisms or environments from which they can transfer knowledge. It is true that many organisms already form part of secondary biology curricula, but I often find that they are passing references in topics. Photosynthesis, and angiosperm reproduction, for example, are appreciated in plants. Fermentation, or pathogenicity are appreciated in bacteria, or maybe simply microorganisms, birds are birds, and reptiles are reptiles, but rarely is they a concrete face to these names, studied in detail. Currently, the concept is king, but conceptual change in a student requires grounding concepts in meaning.
The following summary of my ideas will explain, briefly, how I have been imagening the integration of these two points: An organism-environmental contextualisation, and the development of a biologist’s gaze in the form a biology curriculum.
This post was written through the following philosophical-pedagogical lens:
Short-term: Classroom methods akin to direct explicit instruction (teacher-led)
Long-term: Learning sequences designed around threshold concepts (Meyer & Land, 2006).
Thus, briefly, my epistemic standpoint is that meaning is ultimately construed in the mind of the learner, but emerges from the learning of connected knowledge. While contextual, and integrated curricula have been associated with student-led, or discovery-learning methods, this post was not written with those in mind.
Driving interest and accessing concepts through context
When reading through common university biology textbooks, they often appear dry and vacant of narrative when compared to so-called ecophysiology, or physiological ecology textbooks. The difference lies in the context. Ecophysiology is the study of physiology with respect to its adaptation to environmental conditions, and that alone makes such textbooks a much better read. They provide a grounding in understanding, and a narrative. Where traditional botany textbooks simply describe and explain how plants transport substances for example, ecophysiology provides a narrative of why, and in what conditions. It immediately encourages more evolutionary questions and invites the reader to wonder at the innovating-ability of nature. Rather than being a text about how plants carry out physiological tasks, it provides a context to ask how species have come across innovations that allow them to survive and compete in a particular environment. This is the driver for learning biology, it is not how do these things work? it is how do these organisms deal with these environmental conditions? And how do these species deal with changing conditions in their environment over time?
This is what differs biology from chemistry and physics. While the latter can explain the stuff of the universe, biology explains the dynamic nature of organisms which are capable of adapting to every changing challenges. When I look at a cactus I don’t think: how do plants transport water? I think: how does this cactus deal with such a dry environment? However, when I look at a sequoia and its imposing height, I may very well wonder how it is able to transport water to its canopy.
While human biology is an important part of the curriculum (and so must make regular appearances), major human innovations in cultural evolution obfuscate our relationship to the environment. The innovation of the use of fire, the making of clothes, and tools, to the modern-day society, all complicate matters for generalising deep biological ideas from humans to other organisms, as the human relationship with the environment is complex, constructed, and incredibly varied. I see two possible options here, firstly we could invoke a paleolithic human, or secondly, humans could serve as a point of comparison whilst learning about evolution or system mechanisms in the context of other organisms in their environment, including prokaryotes, fungi, protists, plants, and other animals.
The points of the curriculum that are strictly human biology, such as human reproduction, or the human endocrine system, should clearly be taught in the context of the human. However, human biology should avoid an approach akin to: you have these things, this is how they work.
The nervous system is a vital component of any secondary biology curriculum. However, in typical biology curricula the functioning of a neuron, or a synapse, are commonly taught as an isolated topic, one that takes for granted that students will be able to contextualise the nervous system as they themselves experience its effects through voluntary movement or thought. I don’t think it is enough for biology curricula to say you have a nervous system, here’s how it works. This approach often provides a mechanistic explanation at the cellular level without zooming out again to larger scales. I often find that the big ideas are also absent from such topics: what are the energy costs of having a nervous system? How does a nervous system help a body maintain homeostasis? etc.
Using the big questions as a guide however, I produce these questions: Why do nervous systems exist? What are they good for? How do they solve the challenges faced by animals? These questions can only be answered via evolutionary processes and a consideration of the environment in which they developed. Not all animals with a nervous system think, and not all multicellular organisms have a nervous system, and to understand the system’s significance it may be better to discuss the evolution of the ancestors of cnidaria, for example, and fast processing of senses and quick reactions to stimuli were evolutionarily advantageous. Thus, a topic could be based around a study of a member of the cnidarians, an anemone for example, as the context for studying how the nervous system communicates via impulses. Although non-vertebrate neurons differ in size and myelination, humans can always be brought in the topic as a comparison.
The perspective of biology
Many organisms are only considered in the light of their relationship to humans. This anthropomorphic vision of organisms is typified with the study of prokaryotes in biology curricula. Their appearance is dominated by their relationship to human immune systems and only passingly do curricula mention that many prokaryotes are ‘good’. From the pathogen’s perspective however, the human body is just another environment that offers better conditions for rapid growth compared to other environments. How would a topic on the human immune system look if taken from the perspective of bacterial pathogen?
As organisms differ more from vertebrates I feel that students fail to conceptualise how they experience their environments. For example, as plants live their entire lives in one location they have the challenge of procuring their energy and matter needs from what they have immediately in their vicinity. What the soil contains, is what they will have access to. This is vastly different to animals that can move to new locations to obtain what they require. Seagrass on the other hand, lives in seawater which is in constant movement and can therefore bring minerals to the plant. Terrestrial plants and marine plants differ widely in form: the latter lack the need for roots. But only with a deep appreciation for the environment and how other organisms differ to humans can this be understood.
The organism in its environment as a driver
When I think of geography teachers and their curricula, I imagine experts of abstract principles continually building conceptual understanding via concrete contexts. Let’s say, some geography teachers have great knowledge of a specific African country and use this as the context for building understanding of the big ideas of their discipline. Likewise, English literature teachers have specific novels they use to contextualise abstract ideas of writing, and Art teachers teach via examples of paintings and other works. A biology teacher could have a collection of model organisms and environments that they can use for conveying specific conceptual ideas or biological processes. Just as specific novels used in English literature will depend on culture and society, so the model organisms chosen can be locally important. I know that organisms and environments of all types do appear in secondary biology curricula, but I envisage something more concrete and focused. Rather than organisms appearing only in some questions for applying knowledge towards the end of a sequence on learning, the organism could drive the learning.
When studying plant structure, or photosynthesis, a topic could be focused around a single plant, for example a specific species of grass. When learning about factors affecting photosynthesis a specific agricultural plant, especially one grown in greenhouses, could serve as the context. Transpiration could be learnt via sequoias.
During sixth-form education we teach DNA replication in molecular detail, but the model we use is often that of E.coli. The speed of replication is vital for prokaryotes to compete. A topic could be built around E.coli contextualised in an environment with fierce biotic competition with other bacterial species for domination of resources, before zooming in to the molecular level to view the details of DNA replication.
Some species can be useful for many concepts, such as the (keystone species) beavers, which could serve as a rich ecological study, but could then also be used to discuss kidney function and how they deal with living in water. Carnivorous plants could drive questions on soil nutrition and nutrient cycling. Yersinia pestis could be used for human immunology but also natural selection (of humans and pathogens).
A topic would begin with a driver, a brief study of an organism, its environment (biotic and abiotic factors), and its evolutionary story (close relatives, a cladogram, species age, current distribution, evolutionary history, for example, that grass started expanding rapidly and taking over forested lands around 8 million years ago, etc). This could be a reading activity from a text designed by the teacher. The environmental conditions are explicit and the challenges the organism faces are elicited. Possible driving questions are set up: how do these organisms deal with these environmental conditions? or, how do these species deal with changing conditions in their environment over time? The constant practice and exposure to the big questions when confronted with a new organism and environment would help instill a biologist’s gaze.
Nevertheless, curriculum design should be flexible so that more contextual and less-contextual approaches are used where they work best, rather than adhering strictly to one or the other. It could be that this approach is best used when studying organisms that differ much from humans, such as plants, and prokaryotes, or for specific concepts. There will also be occasions in which the curriculum should derive its context directly from the history of scientific thinking. As such, I view model organisms as an important part of a biology curriculum, but not the entire curriculum.
Developing a biologist’s gaze
Students should begin to comprehend how the big ideas of biology can be generalised to all life. The different organisms used for context will show different surface features, but the study of evolutionary and systemic questions in each case would demonstrate how the deeper concepts in biology are the same; different surface, same deep.
I’ve written before about how physiological processes should be taught vertically (across levels of organisation) rather than only horizontally (within a single level of organisation). This form of curriculum design greatly facilitates a design around Knippels’ Yo-yo teaching (2002), and Maton’s semantic waves (2013), an oscillation between the concrete (and known) and the abstract. In biology and physiological processes, the abstractness increases as learning zooms in to the smaller scales towards the molecular level, and concreteness is increased as learning approaches phenomena visualised at the organismal level. With a topic that is grounded on a specific example of an organism and its challenges in a specific environment, to explain how physiological processes occur in that organism the topic has already begun with a concrete context. Learning can then zoom in and out of the scales of organisation to see how the specific process in question affects the organism-environment relationship. As such, molecular biology provides a perspective for explaining phenomena, rather than being a separated part of the curriculum.
Image by Christian Moore Anderson
There would be an emphasis on the big ideas (maybe one idea is more appropriate for one model organism, but there should at least be some explicit discussion of most of them):
Organisation: The hierarchical nature of living organisms, and how components and mechanisms interact at a level, or between levels.
Energy & matter (the dynamic nature of the system): This would be an important starting point to any topic. How do the model organisms procure energy and matter from their environment? How is it processed in the system across the levels?
Homeostasis: How do the model organisms maintain their state, despite the environmental conditions? Beginning with the environment should be a good primer.
Information: This would be important in several ways: There is reproduction, but in other topics the flow of information should be from the environment to the organism, and from the DNA to the organism (more on this below).
I’ve written before how organelles and micro scale components should not be taught in isolation, but within the systemic processes that they are present. That way, instead of starting biology curricula with a cell biology topic in which ever more detailed drawings of cells and organelles (labelled with functions), would be substituted by an integral learning process in which cell biology is contextualised, until a point in which all the strands can be brought together and students are able to construct their own cell drawings. I also think this is true of other concepts, such as the carbon cycle. If, through this ecophysiology approach, students are continually tracing molecules through systems then the carbon cycle ceases to become a stand-alone topic/concept, but one that is integrally tied to living organisms and their relationship to the environment. At a particularly appropriate point in the curriculum, students could be encouraged to begin tying together what they have learnt in context, to become an abstract idea of nutrient cycling that is also grounded in meaning (to the student).
It could also facilitate an understanding in developmental plasticity and how the flow of information is both from the environment to the cell, and the genes to the cell. The curriculum begins focused mainly on the challenges of the environment, and many discussions can be made towards the plasticity of development and variation amongst a population. Later, when the curriculum moves to look at the role of DNA in more detail, students will already be primed to see the bidirectionality of information. Equally, if they already have a grasp of developmental plasticity, we can expect a weakening of essentialist ideas about species, which should greatly improve their ability to understand how natural selection acts on variation.
When I see urban trees, or walk through the countryside, or see mould on some food, I immediately think about the organism’s environment. I wonder what pressures a population faces, and what innovations (adaptation & acclimatisation) result from natural selection. I think about its physiology and how its systems are organised to obtain and process energy and matter, how it maintains itself in the face of the environmental conditions, and how it propagates itself. This is how I want my students to think. It is a vision of providing, through practise and exposure to examples, a heuristic to approaching novel contexts in nature: Begin with the organism-environment relationship, and then ask the big questions; see it like a biologist. If you've enjoyed this—check out my book, or my other posts.
Christian Moore-Anderson
@CMooreAnderson (twitter)
References
Knippels, M.C., 2002. Coping with the Abstract and Complex Nature of Genetics in Biology Education: The Yo-Yo Learning and Teaching Strategy. Ph.D. Thesis, Utrecht University, Utrecht.
Maton, K., 2013. Making semantic waves: A key to cumulative knowledge-building. Linguistics & Education, 24(1), pp.8–23.
Meyer, J., Land, R., 2006. Overcoming barriers to student understanding: threshold concepts and troublesome knowledge, Abingdon: Routledge.