Answer:
Bottleneck effect
Explanation:
The Bottleneck effect is when species go through an event that reduces its population. The ones that survive have reduced genetic diversity compared to the original population since fewer individuals means there are fewer genotypes.
Stem Cells. Hope this helps.
A good topic idea that could be used can be about ecosystems. Such as how geographic area, plants, animals, weather and landscape make up the types of organisms in that specific ecosystem.