Lecture 5 - Fitness

Question 1

What is fitness?

Answer 1

Relative probability of survival and reproduction of a genotype

Question 2

What is an example of relative fitness?

Answer 2

When how advantageous a genotype is depends on location
Sickle cell heterozygotes are less likely to get malaria
This means this is advantageous in areas with high malaria count, eg Africa, and not advantageous in other areas without it

Question 3

What are the levels of selection?

Answer 3

Species
Groups
Families
Individuals
Genes
Controversy over which part is actually selected

Question 4

What is sexual selection?

Answer 4

Where characters are selected as they are desired by sexual partners, not because they increase fitness
Implies existence of ‘good genes’ that increase survival even though they cause a handicap (eg peacocks)

Question 5

What is altruism?

Answer 5

The behaviour of an animal that benefits another at its own expense

Question 6

What is Hamilton’s rule?

Answer 6

Natural selection of genes that lead to social actions via the sharing of these genes between performer and recipient
Altruism occurs as long as
The relatedness between individuals x benefit is more than the cost

Question 7

What does Hamilton say about direct fitness and inclusive fitness?

Answer 7

Direct = survival and production of offspring
Inclusive = Direct fitness + indirect fitness (fitness of related offspring)

Question 8

What is hymenoptera?

Answer 8

When there is haplodiploidy where the female is diploid and the male is haploid
This means an ant or bee is closer related to its sister than its offspring
Genes are more likely to be passed down to the next generation if rear sisters