BIOL205Z: Animal Behaviour Flashcards
(183 cards)
Hamilton’s rule
rb>c
R=Relatedness
The chance of the other individual sharing the same gene
B=Benefit of Behaviour
The number of copies of the gene produced by the individual being helped
C=Cost of behaviour
The number of copies of the gene that would have been produced if the energy were instead directed towards their own reproduction
Selfish Genetic Elements (SGE’s)
Any element in the genome that can increase it’s allelic diversity within a generation
SGE’s: Transposons
-“Jumping genes”
-90% of the genome (maize)
-50% in humans
T-Haplotype in Mice
-Females pass on to ~50% of offspring
-Males pass on to ~90% of offspring
-Remains at low (ish) frequency, around 10-40%
Segregation Distorters
Alleles that distort segregation in their own favour
Malaysian Stalk-eyed Fly
-X linked sex ratio distorter
-Targets sperm carrying the Y chromosome
-Results in female biased broods
Harem
A group of females associated with a single male, the male typically defends ‘his’ group of females
Supressor
Mutations that correct the phenotypic defects of another mutation without restoring its wild-type sequence
What is social behaviour?
-Aggression
-Territory
-Dominance
-Sexual behaviour
-Parental behaviour
-Co-operation
-Alturism
Benefits of living in groups
1.Reduced predator pressure
2.Improved foraging ability
3.Improved territorial defence
4.Better care of offspring
Sentinel Behaviour
- One member of co-operative group stands guard
-Rest of group foraging
Selfish Herd Effect
-Everyone trying to get to centre to be away from predator
Dilution effect
-Probability of one individual being taken is lower in groups
Costs of living in a group
1.More competition for food and/or mates
2.Increased risk of infection by disease
3.increased conspicuousness
4.interferance with parental care
mandrils
-dominant males sire more offspring
-common pattern in social groups
-can be seen as a cost, but alternative strategy wouldn’t work any better
increased competition
-males compete for mates
-might not get first access to food or there will be inference with food (damage)
increased conspicuousness
-easier to find really large group than 1-2 individuals
-more likely to be seen by predators
interference with parental care
-males kill offspring that aren’t there’s
-common pattern is that only dominant male and female will reproduce
-staying in group might mean you don’t reproduce
Infanticide
-Male lions will kill cubs when they take over a pride
-Also happens in chacma baboons
Prevention of breeding
-In wild dogs, wolves, hyaenas, meerkats, banded mongooses, dominant females will suppress reproduction in subordinates by inducing stress, control or direct attacks
group management
-lions: females stable centre, males come and go
-hyenas: females dominant over males
-in some species, dominance determined each breeding season