Idea: Try modifying the parameters for which numbers on the dice result in survival or death. Narrow the difference between how many survive. Even a small advantage to one group results in an increase in the proportions of that trait growing to dominate the population.

I've attached my modified worksheet. I did not include which paper clip was which group. You'll have to decide this before you start, as well as how many of each group you want to begin with. Think of your scenario/story, and the supplies of paper clips you have on hand.