12, 13

Question 1

what are 3 paradoxes to inclusive fitness theory?

Answer 1

1. anarchy
2. group infedility
3. supercolonies

Question 2

what is anarchy and what causes it?

how common is it?

Answer 2

rare beh syndrome in honey bees, whereby almost 100% of males are from workers in queen right colonies. the cheating anarchist strategy has invaded.
anarchists behave like normal workers, and are not targets of aggression.
perhaps due to genetic basis where 5-10% of workers have active ovaries.
Rare - difficult to detect, and possibly recessive as females must fully express it. rare, only 4 colonies of anarchists known.

Question 3

mechanism of anarchy?

Answer 3

normal colonies have egg marking pheromones, and workers police eggs with the wrong smell. evo of egg pheromones was followed by polyandry.

in anarchistic colonies, there is a breakdown of pheromone control. Eggs laid by anarchistc bees ‘smell’ like queen egg., and policed less.

however in queen less colonies, anarchist eggs are policed - as in absence of the queen and brood, egg marking is switched off.

Question 4

costs of anarchy to the colony

Answer 4

excessive male production - males are expensive.

colonies can support a small no of anarchists, though this has an impact on colony level fitness.

Question 5

benefits to the anarchist

Answer 5

if one female is mother to all the males, it doubles her relatedness to the males reared, and workers from the anarchistic partiline will benefit, even when not laying themselves.

Question 6

example of anarchy in the genome

Answer 6

selfish genetic elements
‘element with characteristics enhancing its own tra
nsmission, to the detriment of the
organism as a whole”
has intra-genomic conflist with parts of the genome with different transmission patterns.
selection to increase transmission of one element even is detrimental to another.
eg, wolbachia, meiotic drivers, transposable elements.

Question 7

how does Wolbachia affect the SR?

Answer 7

in arthropods

1. infect a host female and prevent production of male offspring.
2. can act by feminisation - infects a female and migrates to male offspring, destroys gonads causing male to develop as a female.
3. cytoplasmic incompatibility - uninfected F x infected M - disrupts first cell division so the uninfected female never has functional offspring.
4. Male killer - enters male eggs and prevents cell division.

Question 8

4 examples of group infidelity

Answer 8

1. transposible elements - PK and EK. 50% of human genome.
2. Cancer cells
3. Cooperative breeds - help those which are non related.
4. Social insects drifting between groups (lower level units drift between high level units)

Question 9

4 reasons why an individual may choose to drift

Answer 9

1. Accidental
2. Artefact
3. Indirect fitness benefits
4. Direct fitness benefits
   e. g. Social parasitism

Question 10

why may drifting be accidental?

Answer 10

in apiaries, honey bees seen to drift betewwn nests. maybe because higher than normal density of nests,

Question 11

how could drifting be an artefact.

Answer 11

might just be a part of living in a society, if in close proximity and high density of nests.
Some evidence that it could be purposeful - drift to nests with high relatedness as a potential fitness gain?

Question 12

why may drifting give indirect fitness benefits

Answer 12

observations of Polistes canadensis.
- 56% of wasps recorded visit multiple nests
- Within the population drifting was detected on 94% of nests (31/33)
- Resulting in pairs of nests shared up to 54.5% of wasps
also found that drifters visit nests with higher relatedness - r(drifters to nests visited) = 0.23, whereas r(drifters to nests not visited)= 0.012.

drifters behave like workers, so do invest in the nest

Question 13

example of drifting as a direct fitness tactic

Answer 13

Lopez-Vaamond 2003
32 colonies of Bombus terrestris.
microsatellite analysis of male eggs and assigned paternity to resident workers or drifter workers.
found worker produced males in many colonies as opposed to queen males.
drifters are as rep as residents.

Question 14

how do drifters behave in other nests?

Answer 14

slightly more aggressive, but do worker jobs, so are investing in the nest.

Question 15

2 examples of drifting in the genome.

Answer 15

1. jumping genes -copy and move to a new location, in almost all orgs. can have a regulatory role in gene activation, may be positive or bad for host.
2. bacterial plasmids. drift via horizontal transmission.

Question 16

why do transposable elements exist?

Answer 16

TEs can be very destructive,cause mutation disease..
however beneficial because plasmids encode proteins for survival of hosts eg antibiotic res.
if exons are shuffled, bring together 2 unrelated exons to create new gene products
could potentially repair DNA
increase diversity by altering regulatory regions and phenotypes
important rolein genotype/phenotype evolution.

Question 17

what is a super colony?

Answer 17

Interconnected nests extending 100s-1000s KM
Ecologically dominant and often invasive.
eg Argentine ant, imported into Europe and spread throughout portugal , spain, france, italy.

Question 18

Characteristics of super-colonies

Answer 18

High queen number
• Queens & Workers move among multiple unconnected nests
•Causes inter-linking populations = super-colony
(effectively one huge colony)
• Reduces costs associated with territoriality
• No aggression between nests

Question 19

describe relatedness in supercolonies

Answer 19

Relatedness between nestmates is effectively zero.

creates a problem for kin selection.

Question 20

two ways societies are rich resources

Answer 20

1. to disease parasites, many individuals as potential hosts

2. social parasites - plentiful food supply and potential workers.

Question 21

why are societies susceptible to parasitism?

Answer 21

- Faster spread of infections due to:
High densities
Frequent social contact
Amenable conditions
Close relatives
behaviours eg regurgitation of food for young, transfer of symbionts, fluid exchange.
- Reduced likelihood of detection

this has made a strong selection for defences

Question 22

what is ‘social immunity’?

Answer 22

Collective action or altruistic behaviours
for benefit of the society.
cooperation of group to avoid, control or eliminate parasites.

Question 23

parasite invasion is a multi step process.

Answer 23

uptake from the environment
intake into colony
establishment in nest
spread through colony
spread between colonies

Question 24

2 different types of defence mechanisms

Answer 24

prophylactic measures - minimisation of risk
Activated responses - generation on demand.

each can use a variety of modes, some mechanisms act simultaneously at different stages

Question 25

describe defence mechanisms against social parasites for uptake from the environment stage in invasion process.

Answer 25

prophylactic - 1. division of labour, older individuals go foraging as they are most expendable. 2. Avoidance of parasite rich areas when foraging, communication is important.

Activated response - 1. avoid parasites, hide from active threats eg obvious parasitic flies. 2.reduce cannabilism, avoid infected corpses.

Question 26

example of avoiding uptake from the environment

Answer 26

Leaf cutting ants
Smallest workers hitch-hike on leaf fragments
Reduce risk from parasitic flies and fungal contaminant

Question 27

defence mechanisms against intake into colony

Answer 27

Prevent entry to nest - specialised guards, combine with other workers to defend the entrance,reject parasites and infected colony members.

Question 28

defence mechanisms against establishment within the nest.

Answer 28

1. disinfection using antimicrobial substances
2. Waste management
3. localise infectious outbreak

Question 29

describe waste management as a form of hygeine to prevent social parasites

Answer 29

Specialised workers focus on waste management and dont enter colony much.
designated garbage sites eg for left over food, outside the colony and often down a hill.
‘graveyards’ for dead colony members.

Question 30

describe disinfection of ant colonies, as aprophylactic defence of colony against social parasites

Answer 30

prophylactic - nest hygiene
Disinfection with anti-microbial substances.
ants use Acidic compounds from the metapleural gland, collect solidified conifer resin. use plant compounds as collective defence.
also insert it into nest material.
Wasps produce antiseptic substances from venom glands, very long lasting and protect the next gen too.
Termites - antimicrobial in feces. imp in long lived society when gradual accumulation of infection as time goes on.

Question 31

how do colonies localise infectious outbreak as an activated form of colony defence?

Answer 31

ants - pile fungal spores and cover with soil

Cape honey bees - encapsulate and starve beetles.

Question 32

what 3 ways can parasite spread through the colony be reduced?

Answer 32

1. reduce contact
2. reduce susceptibility by increasing genetic diversity
3. avoid vertical transmission

Question 33

how is contact reduced between castes as a defence against parasite spread through the colony?

Answer 33

spatial and behavioural compartmentalisation. Queen and brood at v centre, with young workers wo have never left the centre, no parasite exposure. outer layers - older worker, oldest are foragers and waste managers.
will abandon nest if all else fails.

Question 34

what tests showed that polyandry causes less parasite intensity

Answer 34

experimental test of polyandry in bumble bees by artificial insemination. colonies from more patrilines resisted parasite better, lower parasitic load.

Question 35

how is vertical transmission of parasites in colonies avoided?

Answer 35

Protect the queen
No tending by infected workers
Protect the brood
Apply anti-microbial secretions
Coat eggs & spray brood with venom
Feed brood anti-microbial peptides
Trans-generational transfer of immunity

however, there is little selection to minimise horizontal transmission.

Question 36

what do slave makers do?

Answer 36

slave makers, Protomognathus americanus
steal eggs from other colonies and raise in own nest as own brood, make them their workforce.
Best defence is to spot invading slave makers and fight. (dont abandon colony as it is a precious limited resource with the eggs inside, although under extreme circumstances might).

Question 37

study of host response to slave makers

Answer 37

Jongepier et al 2014
host species Temnothorax
studied populations varying in parasite pressurefro slave makers Protomognathus americanus.

probability of evacuation increased, no. immobilising workers decreased with higher parasite pressure,

Question 38

why do some victims appear to tolerate parasites?

Answer 38

probably in a co-evolutionary host-parasite arms race and there is an evolutionary lag.
possibility: constraint on victims - costs of evolving resistance outweighs benefits. - parasitism is rare, recognition errors are costly and defence is expensive.

maybe then, the victim is selected to become more tolerant

Question 39

example of tolerance to parasites

Answer 39

Fork tailed drongos kleptoparasitise a range of species: meerkats, pied babblers and sociable weavers.
sophisticated cheats with a flexible strategy.
use physical attack and false alarm calls, target juveniles who are less experienced and more vulnerable.
also act as effective sentinels.
pied babblers respond as they would to their own species sentinel call, so increase food intake. perhaps it is a manipulative signal so there is more food available to take.
babblers get consistent continuous benefit in more food and pred alarm call.
this mitigation benefits lower cost of parasitism.

Question 40

experiment testing how altruism is maintained in unicoloniality

Answer 40

There are ‘clusters’ within the super colony with low (but positive) relatedness among cluster-mates, relative to between-cluster mates.

genotyped microsatellites and mit from workers from 3 populations.

found cryptic structuring within population, moderate pos relatedness among clustermates, suggesting a role of kin selection.
Queen and worker dispersal is limited, whereas dispersal of males is high.

Question 41

are unicolonial groups evolutionarily stable?

Answer 41

biological puzzle as the adaptive kin selection in small groups is no longer v important.
perhaps just short e=term ecological success but evolutionarily a dead end and unstable.
could lead to degradation in worker beh.
supported by fact that of 12,000 ant species, only 31 are unicolonial, and there are no unicolonial clades.

Question 42

what are 3 suggested pathways to unicoloniality?

Answer 42

1. Inter-group and intra group conflict drives the evolution of the ‘superorganism’?
2. fusion of smaller colonies - promotes re acceptance of queens by maternal colony. establish new colony by budding, causing a netwrok. costs of aggression and comp reduced but halves R.
3. Genetic recognition bottleneck.
   invasive populations, reduced kin recognition.

Question 43

what 4 things do we still not know about unicoloniality

Answer 43

1. mechanism for maintaining unicoloniality
2. why dont all larvae wnat to be queens
3. why dont all workers turn anarchistic - maybe theyre all sterile?
4. How can worker behaviour be maintained in such low R? Worker- expressed genes are not under selection so beneficial mutations cant be maintained, and deleterious ones cant be eliminated.