Let's use this new knowledge for a fun project—modeling evolution. We are going to create a closed, simplistic representation of an ecosystem, containing animals that can age, breed, and survive (or not!) in harsh conditions. To test different scenarios, we will produce a few of those ecosystems, islands, each having different environmental conditions. We'll run the experiment by simulating the behavior of those systems and gather statistics on their dynamics over time. In order to do so, we will build a dedicated class for each of those entities.