This statement means that evolution has happened by getting the genes of the right trait expressed at the right time to help adaptability.
Explanation:
Evolution is a result of natural selection which emphasize on the survival of the fittest. But the occurrence of this trait has been possible with genetic variation. It means that if the genes for the particular feature is not present in the genome how would it occur and adapt to the environment. Thus, evolution promotes the most available option for the adaptation and hence for natural selection.
We can conclude that all features are not adaptable some are the results of genetic drift or mutations.
In case of cheetah, the faster running genes would have been there they got expressed over the period of time for better adaptability.
Hello!! The answer would be A - The SA node. It is known as the "pacemaker" because it initiates the heart's rhythmic contractions. I hope I helped!! Have a great day. :)
