You can also discuss why a recessive gene with an unfavorable trait remains in the population. Ultimately, we would like the students to understand that, in order for evolution to occur, there must be a change, over time, of the gene frequency of the organisms. Teddy Grahams Divide the students into groups of two and have them read the introductory story that describes the environmental conditions affecting favorable and unfavorable traits. After the story is read, have students follow the prescribed procedure and predict the outcome of each population of bears. You can tell the difference between them by the way they hold their hands.
Happy bears hold their hands high in the air, and sad bears hold their hands down low.
Happy bears taste sweet and are easy to catch. Sad bears taste bitter, are sneaky, and hard to catch. Because of this, you eat only happy bears. First, obtain a population of bears, and have your students record the number of happy bears, sad bears, and the total population for each generation in a data table. Second, eat three happy bears.