Organisms used to be classified in the earliest times according to their size. As science progressed, they started getting organized by their physical traits and now they're organized by traits found in their species that are not found in others based on the theory of evolution. They are classified according to how they developed from a starting organism.
Answer:
Cross-pollination.............
A gene pool changes throughout evolution this could be natural selection, genetic drift or a mutation. A gene pool does this to adapt with the needs of the environment it is in
