Models in Science
Scientists often use models to investigate and explain their observations. Models are important tools. A scientific model is an idea or group of ideas that explains something in nature. It is a representation that helps scientists understand and predict events that are difficult to observe directly. The computer simulations below are an example of a scientific model that can be a useful tool for understanding some aspects of inheritance.
Another kind of model used in science is called a "model organism." These living models are chosen because they have certain qualities and characteristics that make them well well suited for a particular study. Paul Williams originally developed Wisconsin Fast Plants as a model of the closely related cabbage plants he studied.
Keep in mind that models are a tool, and just like many tools, they are useful for some work, but not for everything. Models have limitations. For example, the simulations below involve pollination among only two "parent" plants, yet in reality, most pollination would involve many plants randomly sharing pollen, depending on the pollinator.
As you explore the following simulations, look for ways that the models accurately represent what would take place in nature and make note of the limitations, places where the model developers built in assumptions or limited interactions to make the model serve a specific purpose.
For more information about model organisms in science, there are animations, movies, and background information at Teacher's Domain.
Inheritance Simulation #1
Observing Wisconsin Fast Plants™ Seedlings
Simple inheritance of the gene that regulates the expression of anthocyanin, a purple pigment found in many plants, including Wisconsin Fast Plants™. This simulation shows the expression of the purple stem trait in 2–3 day–old seedlings, with or without revealing the genotypes.
Inheritance Simulation #2
Observing Wisconsin Fast Plants™ Seedlings
Simple inheritance of the gene that regulates pea seed color. This simulation aligns with some of Mendel’s early observations, and it can be run with or without revealing the genotypes.
Inheritance Simulation #3
Observing One or Two Traits in Wisconsin Fast Plants™
Variety of simulations, including nutrient level impact on growth and development, and inheritance of one or two traits. These inheritance simulations show larger population numbers than Inheritance Simulations #1 or #2. The simulations can be run with or without revealing the chromosomes (genotypes).
