Social Behaviours: Altruism to Spite

Question 1

Darwin’s “special difficulty”

Answer 1

neuters or sterile females in insect communities

Question 2

Organizational levels within species

Answer 2

population
phenotypes
sexes
individuals
chromosomes
genes

Question 3

How do populations evolve?

Answer 3

Through changes in gene frequencie

Question 4

Inclusive Fitness

Answer 4

Altruism at the individual level = selfishness at the level of genes

Natural selection tends to design organisms as inclusive fitness maximizers

Question 5

Female ground squirrels

Answer 5

more likely to give alarm calls than males (only do before dispersal)

particularly when there are close relatives nearby

Question 6

alarm calling in prairie dogs

Answer 6

not kin-selected

Question 7

Self-restraint in tiger salamanders

Answer 7

highly cannibalistic when crowded (direct benefit of eating another salamander, high cost to eaten salamander)

more likely to cannibalise (with) non- relatives

Question 8

Kin recognition

Answer 8

Reared together always reduces aggression, but relatedness matters when reared apart

Always average relatedness,
but rare “green beard genes” combine signal, recognition, and cooperative response

Question 9

Spite

Answer 9

Harm yourself and also harm others

kin-selected trait
- when individuals can recognize others to which they are negatively related

Question 10

Relatedness

Answer 10

genetic similarity RELATIVE to population mean

= altruism towards secondary recipients benefit because spiteful aggression removes less related competitors

Question 11

Soldiers in polyembryonic wasps

Answer 11

sterile (pay a cost)

kill less- or non-related larvae

free up resources for closer relatives