Answer:
They were introduced by humans
Explanation:
I attached a PDF document, just take a part of it that seems to work the best, and put it through a paraphrasing tool so it doesn't get flagged for plagiarism
its B...
because a composite cell has a cell wall, vacuole, and cell membrane but doesnt include any of the plant cells so i know its B
Phase 1: Starts with the separation between populations. Separated populations become adapted to local conditions and become genetically differentiated over time.
Phase 2: Genetic isolation is completed, reproductive isolation develops mostly in the forms of prezygotic RIMs.
The most likely explanation for this phenomena is that this is a result of natural selection.
What actually happened?
When the insecticide was introduced, it killed all of the organisms that were vulnerable to it. However, there was a portion of the population that was immune. Since the immune individuals were the only ones that have survived and left offspring, after some generations in the population of this organism there were only their descendants that have the resistance to the insecticide.
