Levels of selection

Question 1

What are the 6 levels of selection?

Answer 1

1. Genes
2. Traits - can evolve independently of genes
3. Individuals
4. Population - regulation of numbers
5. Species - rates of speciation
6. Higher taxonomic levels - more successful lineages predominate

Question 2

What did Wayne Edwards suggest with regards to animal dispersion and social behaviour?

Answer 2

• Populations regulate their size in order to survive lean periods
• e.g spontaneous abortion in high density populations of rodents

Question 3

What are epidietic displays?

Answer 3

Ideas that displays such as the dawn chorus can assess the population size

Question 4

How did Maynard-Smith counter the views of Wayne Edwards?

Answer 4

• believed model was not evolutionarily stable

- populations regulated by increase/decrease in births/deaths in response to lack of resources

Question 5

Describe the idea of “group selection”

Answer 5

The idea that the fittest groups cooperate and out-compete more selfish groups

Question 6

What is function & effect?

Answer 6

Idea that why a trait has been evolved/maintained by evolution must be explained

Question 7

What explanation is there for the ‘Bruce effect’ in rodents?

Answer 7

With arrival of new males infanticide is very common so spontaneous abortion avoids unnecessary reproductive effort

Question 8

Define indirect fitness

Answer 8

Reproductive success of your relatives and the continuation of your genes

Question 9

What is Hamilton’s rule?

Answer 9

That an organism will be ‘altruistic’ if the benefit outweighs the cost when adjusted by the coefficient of relatedness (r)

Question 10

How does the Hamilton’s rule explain behaviour in social insects?

Answer 10

Social insects are diplo-haploid (males are haploid) and therefore relatedness between sisters is higher than between offspring

Question 11

What usually defines altruism between non-relatives?

Answer 11

It is reciprocal

Question 12

What is NeoDarwinism?

Answer 12

Seeing evolution as mostly changes in gene frequency

Question 13

Define kinship selection

Answer 13

Idea that worker ants provide more of a benefit down to reproductive members of the colony, developed by Darwin

Question 14

What is Hamilton’s equation for kinship selection?

Answer 14

-c (deductive fitness) + br (benefit to recipient) > 0 Then behaviour is favoured by natural selection

Question 15

What are the 4 mechanisms of inclusive fitness

Answer 15

mutual benefit: c<0 b>0

selfishness: c<0 b<0
altruism: c>0 b>0
spite: c>0 b<0

Question 16

What is relatedness?

Answer 16

Measures genetic similarity relative to the population average

Question 17

What is the greenbeard effect?

Answer 17

• If a single gene encodes a detectable marker and helpfullness to the marker then the gene is more likely to be passed on

Question 18

What are the 3 mechanisms for kin selection?

Answer 18

1. Limited dispersal - if relatives are in close area, positive acts are more likely to be advantageous to relatives
2. Kin selection - ability to identify relatives
3. Greenbeard effect