Fitness and Selection

 Absolute Fitness is an average number of descendants one organism has over that organisms lifetime. As for relative fitness it is when an organism has the highest amount of decendents compared to other organisms. So the equation for relative fitness is absolute fitness divided by the average fitness. Positive selection is when a population of an organism goes through mutations to become more successful. In this example below over time the brown caterpillars start to produce more decensdants and come the dominant species over the purple caterpillars.