For this experiment, artificial selection is made by the scientists where traits of benefit are made to be present in the gene by high mutation rate so that the adaptability increases.
Step-by-step explanation:
Natural selection is a process by which a organism with beneficial traits survive and reproduce in large numbers. They adapt to the environment very quickly and pass on these traits to its progeny which are at the better survival zone.
The mutations for the beneficial traits in certain genes caused the bugs to adapt to their environment well. When mated, they pass on the traits in every generation. It is also said that those organisms who did not get mutated eventually died.
The faster the mutation rate, the faster the mutated bugs with beneficial traits will appear in each generation.
From the graph it can be said that those bugs who could not bear the mutation they died and hence did not appear in the next generation only those bugs who could cope up the environment survived.