E. coli to Elephants: Extrapolating from Models
In 1954, the famous French scientist Jacques Monod’s uttered the phrase, “Anything found to be true of E. coli must also be true of elephants, only more so.” E. coli is short for Escherichia coli, a very common bacterium that lives in the human intestine. E. coli is useful for humans because it is a major component of our normal intestinal flora that promotes general health. It is especially useful to scientists, however, because it has severed as a simple model to study countless cellular phenomena that occur in all living cells, not just bacteria… including elephants.
Monod’s point was that, even though only a bacterium, E. coli is—biochemically—more similar to an elephant than it is different. Further, E.coli reproduces quickly, offers a nearly infinite array of mutations to study, and fits easily on a microscope slide. In short, it offers a convenient and powerful model for studying higher forms of life.
Models have done more to push modern science forward than nearly any other tool, perhaps rivaling mathematics itself. Models allow us to conceptualize and experiment on systems that are too large (like the Universe) or too small (like atoms) to easily study in the lab. Likewise, having models that represent human beings allows scientists to perform experiments that would never be possible otherwise. Watson and Crick worked out the structure of DNA by using models constructed of wire and paper. The monk Gregor Mendel used simple pea plants as a model for the inheritance of genetic traits that today help predict the occurrence of genetic diseases in the human population. Tidal waves are studied in troughs and meteor impacts are modeled with marbles and playground sand. Computer modeling and simulations allow scientists to study phenomena ranging from intergalactic collisions, origins of the universe and the prediction of tomorrow’s weather.
Models in Science Education
In science education, we should build on the student’s natural tendency to understand and use models from the earliest possible ages. When using models in science, we are essentially saying things like, “Hey, let’s pretend that…” or “What would happen if we…” Simply listen to small children playing on the back porch and you will hear nearly identical remarks: “The stairs are a mountain, you can’t come up here…”
As I wrote in August, children benefit from all sorts of scientific modeling, as it is familiar to them from their own games and it gives them a chance to interact with difficult, often abstract concepts on terms that they can easily understand and experiment with. Indeed, a child investigating a double helix model might very well come to the same conclusions as Watson and Crick did regarding its structural integrity, and in much the same way.
At LabLearner, we incorporate modeling at all levels of our science curricula. As an example of a simple model that we use in second grade when discussing the water cycle, students model condensation and precipitation using a 400ml beaker, a kitchen sponge, water, and a dropper. In this model, the bottom of the beaker represents the Earth’s surface and the sponge represents a forming cloud. As water is added to the sponge, a certain amount is retained by it, which represents the condensation step of the water cycle. However, as students add more and more water, eventually the “cloud” cannot hold any more water and precipitation falls from it and splashes down to the Earth’s surface. Second graders have no problem whatsoever in conceptualizing this model. Further, as they walk home after school, they can look up into the sky and see real clouds and reflect on the clouds’ capacity to hold a certain amount of water. When they are caught in a rain shower, they can conceptualize that the clouds became “saturated” and could hold no more water and precipitation has occurred.
Models give students and scientists alike the tools to extrapolate from representations of objects and systems. Science educators seeking to teach their students vital critical thinking skills, applicable in any subject, should offer their students many chances to indulge their natural affinity for scientific modeling.
What is LabLearner?
LabLearnerTM is a research-driven science education system that targets Pre-Kindergarten through 8th grade level students...