This is a remix of https://www.exploratorium.edu/snacks/bean-counter-evolution

I love the above activity, and I think it is a great way to demonstrate natural selection and the process of evolution. My coworkers and I brainstormed some extensions or modifications that go along with the original activity. 

First modification idea - If short on time, you can mix the types of utensils within the group, have them compete for the beans, and then the predator that captures the least amount will "die" and become the offspring of the predator that captured the most. For example, if the student in the group with the chopsticks captured the least and the finger predator capture the most, then in the next round, the chopstick student will instead use their fingers as a new finger predator. Continue until everyone in the group has become the same type. 

Second modification idea - Instead of giving each group a mix of different beans, give each group a single type of bean and make them very different from the others. For example, one group could get a wide flat bean, one group could have rice, one group could have split peas, one group could have gelatin, one group could have cooked spaghetti, etc. Follow the rules of the first modification, and see if each group ends up with a different "best" type of predator. This is a great way to demonstrate that the fittest adaptation depends entirely on the environment.