Answer: Divergence evolution or divergent selection
Explanation:
The divergent evolution/divergent selection can be defined as the process of accumulation of differences between the related populations lies within the species. This process leads to speciation.
This occurs when the two populations of the same species get separated by a geographic barrier. The separated members of the same species experience different selective pressure that are responsible for adaptation in the new environment.
The appropriate answer is C. ANCESTRAL FINCH. The study of these birds on the Galapagos island led to Darwin proposing his theory of natural selection. Darwin collect and preserved samples of the finches he observed while on his travels.
He did not observe anything unique about the birds until after he returned home. He focused on the differences in the beaks of the birds. It is then that he started to work on his revolutionary theory.
A population decrease in primary producers would affect the ecosystem negatively because everyone who ate the primary consumers would have a lack of food.