They became adapted to their new environment and became new species which then were not able to produce fertile offspring.
Contour intervals between contour lines
Answer:
In general, these Allee effect mechanisms arise from cooperation or facilitation among individuals in the species. Examples of such cooperative behaviors include better mate finding, environmental conditioning, and group defense against predators.
Explanation:
The answer you are looking for is D, the cell membrane!
Not sure how to explain it, it's biology, mostly memorization.