NATURAL SELECTION Click to add text Some mice are eaten by birds Mice reproduce, giving next generation A population of mice has moved into a new area where the rocks are very dark. Due to natural genetic variation, some mice are black, while others are tan. Tan mice are more visible to predatory birds than black mice. Thus, tan mice are eaten at higher frequency than black mice. Only the surviving mice reach reproductive age and leave offspring Because black mice had a higher chance of leaving offspring than tan mice, the next generation contains a higher fraction of black mice than the previous generation