write about evolution by using beetle population.
Answers
Situation 1: Green beetles got the survival advantage or they were naturally selected as they were not visible in green bushes. This natural selection is exerted by crows resulting in adaptations in the beetles to fit better in their environment.
Situation 2: Blue beetles did not get survivals advantage. Elephant suddenly caused major havoc in beetle population otherwise there number would have been considerably large.From this we can conclude that accidents can change the frequency of some genes even if they do not get survival advantage. This is called genetic drift and it leads to variation.
Situation 3: No genetic change has occured in the population of beetle. The population gets affected for a short duration only due to environmental changes.