evolution of coop breeding 2

Question 1

cooperative breeding is explained through which model:

Answer 1

Emlen 1982
Ecological constraints hypothesis
- independent breeding is constrained
- grown offspring delay dispersal and “stay at home”
- grown offspring help to rear later broods

Question 2

coop breeding: direct benefits:

Answer 2

1) current reproduction
2) increase future reproduction
- – acquisition of skills/mate/territory
- – group augmentation - better survival in group

Question 3

coop breeding: indirect benefits:

Answer 3

increased fitness of relatives

• – better productivity
• – better survival of breeders (lighten load)

Question 4

eusociality =

Answer 4

‘true sociality’ with non-reproductive castes

-wasps, termites, bees

Question 5

does high relatedness play key role in transition of asocial to eusocial:

Answer 5

• monogamy hypothesis: strict lifetime monogamy = relation to offspring & siblings = 0.5. any benefit from raising sibling rather than offspring favours cooperation
• predictions: species passed through ‘monogamy window’ & multiple mating occurred later
• all eusocial did come through monogamy window
• –LIKELY TO BE TRUE, kinship important

Question 6

non-social organisms –> eusocial organisms: the cooperative transition

Answer 6

facilitated by relatedness, determined by strict lifetime monogamy
—kinship important in evolution of eusocial insects

Question 7

does the monogamy hypothesis apply to other taxa?

Answer 7

• Mammals = supports monogamy hypothesis

- birds = also agrees with monogamy hypothesis

Question 8

cooperation breeding has evolved in kin groups:

Answer 8

HATCHWELL 2009
look at all cooperative taxa, see how many species cooperation occur in kin and non-kin groups
-majority cooperate in kin group (92% of species)

Question 9

why is kinship so important in cooperative breeding:

Answer 9

• group of close relatives, less conflict within groups (inbreeding avoidance)
• kin-selected helping

Question 10

a sceptics view of evidence for kin selection importance in cooperative breeding:

Answer 10

1) group productivity increase may be due to individual / territory quality –> laughing kookaburra
2) direct benefits of helping under-estimated, fairy wren (splendid & superb) over 70% of EPP
3) costs of kin competition ignored
4) there is little evidence for active kin discrimination, more related, the more they help: lots of evidence for this: bell miner more r, more help

Question 11

kin selection driving force for coop behaviour

Answer 11

yes,

was for then against (sceptic views) and now for.

Question 12

kinship importance across species:

Answer 12

variable, unimportant in some species (dunnock)