A class studied lizards with two heritable trait versions: lighter skin and darker skin. They lived in a cool rocky habitat. After cool mornings made heat absorption important, students recorded survival and average offspring per surviving adult. Trait | Start (out of 100) | Survival to adulthood | Avg offspring/adult ------|--------------------|-----------------------|-------------------- lighter skin | 55 | 40% | 3 darker skin | 45 | 80% | 5