Component 2.6 - Evolution And Selection

Question 1

What is the founder effect?

Answer 1

When a small number of individuals get isolated and start a new population and they have a very different allele frequency to the rest of the population.

Question 2

Give an example of stabilising selection

Answer 2

Baby weight

• small babies lose heat rapidly and are susceptible to infection
• large babies do not pass through the birth canal as easily and survive less well.

Question 3

Give an example of directional selection

Answer 3

Fish with larger fins escape prey more easily

Question 4

Give an example of disruptive selection

Answer 4

Salmon that are small can “sneak” to mate and large makes can gain access to females by fighting and medium makes cannot use either strategy.