Bottleneck effect

Question 1

The bottleneck effect is similar to the

Answer 1

founder effect

Question 2

It occurs when

Answer 2

It occurs when a previously large population suffers a dramatic fall in numbers

Question 3

A major environmental event can massively reduce the number of individuals in a population which in turn reduces the

Answer 3

genetic diversity in the population as alleles are lost

Question 4

the major environmental event leads to survivors

Answer 4

The surviving individuals end up breeding and reproducing with close relatives

Question 5

Example of the bottleneck effect
A clear example of a genetic bottleneck can be seen in cheetahs today

Roughly 10,000 years ago there was a large and genetically diverse cheetah population

Most of the population was suddenly killed off when the climate changed drastically at the end of the Ice Age

As a result, the surviving cheetahs were isolated in small populations and lots of inbreeding occurred

This meant that the cheetah population today has a serious lack of genetic variation

This is problematic for conservation as genetic variation within a species increases the likelihood that the species is able to respond (survive) in the event of any environmental changes

Remember the environment exerts a selection pressure on organisms

Question 6

Exams often ask questions about how the process of natural selection occurs for a certain species. The principles of natural selection described above are always the same! You just need to edit the details to make them specific to the question