Flashcards in Part 3 - conflict Deck (81)
Sexual conflict is rife in nature, including within families.
Langurs live in ... societies with a single reproductive male. There is a turnover of males through time, with males competing to become the dominant male and monopolise reproduction within the group. In one particular study group, four males 'ruled' over 5 years and, during this time period, 83% of ... .... This is so that females come into ... more quickly, to ensure that their short time in reproductive dominance results in the maximum amount of offspring. Obviously this is not very beneficial for a female.
matrilineal, infants died (infanticide), oestrus
It used to be thought that infanticide was a ... behaviour resulting from males with high testosterone, but we now know that it is adaptive. It not only occurs in males, but also females, for example in ... .... This is a ... species from central America. These females have two or more males living on their territory. She will mate with them and produce a clutch of eggs for each male to look after. When the females were experimentally taken away from their territories...
wattled jacanas, polyandrous, a new female would claim the territory and kill any original broods and destroy any current breeding attempts. The male would then accept a new clutch of eggs from the new female and raise those.
- adaptive for individuals who have a short reproductive tenure within a group
Acorn woodpeckers are co-breeders. These co-breeding groups are usually relatively highly related (~... are first order kin, ~... unrelated). Yet 38% of all eggs laid in joint nests are...
destroyed by co-breeding females
Females destroy eggs that are laid in the nest before they start laying their own eggs (i.e. eggs likely to belong to likely related co-breeders). Eggs laid ... in the sequence of laying within a given nest have a higher probability of being destroyed. This is an example of reproductive conflict and suppression by co-breeders (each female trying to maximise her own representation of offspring in a given breeding attempt). This is because there will be ... among the offspring for limited resources. Despite the close relatedness of females within a group, this is an adaptive strategy.
Meerkats are co-breeders that live in relatively large groups of ...-... individuals. Within each group, there is typically a dominant ... and dominant ..., who attempt to ... reproduction. There are ... females (normally relatives of the dominant) and ... males (who normally disperse between groups and are ... immigrants). The society could be described as ....
3-50, female, male, monopolise, subordinate, subordinate, unrelated (to main breeding pair), matrilineal
Dominant females attempt to monopolise reproduction, but subordinate females, especially in large groups, also attempt to have litters. There are plenty of subordinate males around willing to oblige. However, we see marked differences in the result of pregnancies between dominant and subordinate females.
Dominant females have on average ... pregnancies per year, with ... of these failing and only ... of litters failing (all pups dying). Subordinate females only have ... pregnancies per year, with ... of these failing and ... of their litters failing. Clearly, dominants are very effective at monopolising reproduction.
3.1, 18%, 13%,
1.2, 33%, 71%
(so almost double pregnancy failure rate and over 5 times higher litter failure rate)
This is because the breeding of subordinates is costly to the dominants. Pup ... at independence is significantly higher when the dominant breeds alone than when she breeds synchronously with a subordinate. This is a predictor of future reproductive success
- chance of becoming dominant in future greatly affected by weight/size - subordinate breeding compromises (as more pups to share food and care and compete with)
How do dominant females protect their monopoly and their offspring's future reproductive success?
By evicting subordinates (more likely if less related and more likely the closer you get to the dominant's birth date) and infanticide (which leads to subordinate litter failure) - other subordinates often help with this
In other species of mongoose, for example the ... mongoose, ... breeding (breeding by multiple females synchronously) is routine behaviour. There is still a cost to having multiple litters at the same time, as there is competition among the offspring over care and in the future. In these mongooses, small subordinate females pre-empt future competition via spontaneous ... in ... groups and under ... conditions.
banded, plural, abortion, large, harsh (study looked at lower rainfall and higher number of co-breeding females)
When thinking about eusocial insects, it is often assumed that workers are sterile. However, this is not always the case. In some social insects, workers retain functional ... and can produce ... (i.e. from unfertilised eggs).
In these (haplodiploid) insects, worker-brother relatedness = ..., worker-son relatedness = ..., and worker-nephew relatedness = ... (as worker-worker relatedness = ... and .../2 = ...)
So workers should lay eggs to produce sons and allow sisters to produce nephews. (as nephews are more closely related to them than their own brothers - better to help sisters raise sons than it is to raise brothers)
0.25, 0.5, 0.375, 0.75, 0.75, 0.375
Queen mating ... affects relatedness. If the queen mates with many males, it is likely that most sisters will only be related via their mother (so r = ...). This is why ... is so important in the evolution of eusociality.
Relatedness between members of a colony rapidly diminishes as the ... of a queen increases
frequency, 0.25, monogamy,
When a queen mates multiply, she prefers sons (r = 0.5) to grandsons (0.25) - i.e. worker sons
Workers prefer sons (0.5) to brothers (0.25) - i.e. queen sons
Workers prefer brothers (0.25) to nephews (0.25/2 = 0.125)
So workers should...
prevent other workers reproducing, known as worker policing (when queens mate multiply)
This was tested by adding honeybee eggs into the hives of study colonies. These eggs could be ...-... or ...-.... The survival of these eggs was monitored over a number of hours. Workers were observed ... the eggs of other workers. This is evidence of worker policing.
queen-laid, worker-laid, removing
In Dolichovespula wasps, queens mate a variable number of times (sometimes many, sometimes monogamous). This means there will be a range of worker relatedness across colonies (can be calculated).
Found that, in those colonies where worker relatedness is high (monogamous queens), there was...
However, when worker relatedness was reduced (because queens had mated multiple times)....
This was due to...
a high proportion of males produced by workers
there was a very low proportion of males produced by workers
worker policing (destroying eggs laid by other workers when average relatedness was lower due to queen mating multiple times)
Data across species with varying levels of queen promsicuity shows that...
those species with a higher average relatedness among workers have higher reproduction by workers
Policing serves to enforce ....
In those species where policing is very effective (workers are good at discriminating the eggs of other workers from those produced by a queen), fewer workers attempt to reproduce.
Another consequence of variation in worker relatedness among colonies is that workers will sometimes...
kill the queen - if the queen mates once, workers are more closely related to their nephews than their brothers. If the queen mates multiply it is the other way around. In Dolichovespula arenaria, when the colony switches from producing workers to producing sexuals (including males), workers kill the queen in monogamous colonies (to protect high worker pedigree relatedness)
(prob listen again - lecture 10 slide 29)
Avian e.g. of conflict between breeders and helpers: ...-... ...-.... These birds live in colonies of extended families and multiple breeding pairs. Each pair has a burrow in a bank of sand and helpers. A lot of harassment occurs within these groups (e.g. chasing and interfering in ..., blocking nest access, ... removal). The harassers are always paired (so not looking for reproductive partner) and usually closely related. ... of victims of harassment became helpers at the nest of the harasser.
Hypothesised that harassment is used to...
Does harassment to recruit helpers make sense?
Assuming breeders and helpers are close kin (r = 0.5) - typically the case:
A breeding pair alone produce ... young. Every helper adds ... young (very significant effect on productivity of pair)
From a helper's perspective, helping has about the same pay-off as breeding (siblings as related as offspring)
From breeders' perspective, a helper breeding alone produces 0.51/2 = 0.26 young for the breeder
This means that a helper contributes more to a breeder's inclusive fitness as a helper than if it breeds independently, yet from the helper's point of view it doesn't make much difference.
(remember assuming that r = 0.5)
Found that recruitment of victims of harassment as helpers varied with ....
75% recruited when r = 0.5
35% when r = 0.25
0% when r < 0.125
- degree of conflict and outcome of conflict is a function of relatedness
Conflict over inbreeding: acorn woodpeckers. Inbreeding is bad as it exposes deleterious ... mutations which may have adverse consequences for the fitness of offspring. Avoidance of incest is adaptive.
In cooperative systems, there is a lot of potential for incest, as there are many related individuals of the opposite sex living in close proximity.
In acorn woodpeckers, there is potential for incest when a breeder ... and is replaced by a ... who may be related to the remaining breeder. However, just ... of 75 cases of potential inbreeding resulted in incest. How is incest avoided?
dies, helper, 5%
power struggles between helpers and breeders which generally (50% of the time) are resolved within a month, but can last up to 3 years.
If there was a female breeder and helper sons, ... of the time the helpers left and ... of the time the breeder left.
If there was a male breeder and helper daughters, the helpers left ... of the time and the breeder left ... of the time
(males are more dominant in this species)
In red-winged fairy-wrens, inbreeding can be avoided by seeking...
Maternity is typically monopolised by a female within a territory. ~40% of paternity within a group is generally obtained by a dominant male, and a very small amount by helpers. However, ... of paternity is also obtained by an extra-group dominant male.
extra-pair paternity (very high rate), ~40%
Looking across multiple pairings, extra-pair paternity is higher when...
the relatedness of the social pair (dominant male and dominant female) was higher
Trivers' parent-offspring conflict model:
with increasing parental investment, the benefits show a...
with increasing parental investment, the cost ... at an ... rate, as the more invested in offspring, the less available to sustain themselves
curve of diminishing returns (offspring can only survive to 100% - plateaus)
Since the offspring only shares 50% of their parents genes, the cost will be the same as...
the cost to the parent divided by 2 (see phone pic)
The optimal parental investment, from the parent's point of view, is where the...
difference between the benefit and cost curve is highest (maximum benefit to cost ratio)
- same true of offspring curve
We find that optimal parental investment for the parent is...
(generally) less than the optimum for offspring - this creates a conflict