EE Lecture 7: Social Evolution Flashcards
what are the potential benefits of group living
- finding food
- accessing food
- predation avoidance
- social benefits
what are the social benefits of group living
learning is easier finding mates easier sharing info easier assistance in offpsring rearing division of labout
what are the benefits of predation avoidance in group living - how is this carried out
vigilance effect
dilution effect
selfish herd effect
confusion effect
what is the optimal group size
max benefits and min costs (greatest difference between the two lines)
how can social group living be viable
need valuable food patches, clumped in space and time
patches need to be large enough to support several individuals, otherwise it would cause animals depending on the patch to compete
give an example of animals that use the “vigilance effect” to avoid predation
capuchin monkeys - animals in small groups spend more time scanning for predators
what are the potential costs of group living
increased competition for resources (food and mates)
increased risk of disease
increased conspicuoiusness to prey
increase chance of cuckoldry
what is the socioecological model
males arrange themselves with respect to females, who arrange themselves wrt food
what are the main diet types
frugivory - fruit
folivory - leaves
gumnivory - insects
faunivory - fauna
what is a frugivore
fruit eater
what is a folivore
leaves eater
what is a faunivore
eats fauna
what is a gumnivore
eats insectsq
how do plants defend against being eaten
how have animals overcome this
plants produce tannins&phenols
older plants = increased tannins&phenols
so animals tend to eat younger leaves as easier to digest
primates have colour vision for spotting young red leaves
why is a diet needed
BMR
Active metabolism
Growth
Reproduction
what is the BMR
basal metabolic rate - energy expended while an org is at rest and digestive system inactive
how does the SA:V ratio vary as size increases
SA:V ratio decreases as overall size increase
which has a bigger SA:V ratio, mouse lemur or gorilla
mouse lemur has a larger surface area to volume ratio
what relationship is there between SA:V and metabolism
a smaller animal with a higher surface area to volume ratio will have a higher metabolism therefore eat high quality insects, gum +fruit
what does a gorilla eat, why
lots of low quality vegetation due to having a smaller SAV ratio and slower metabolism
what is a mucin
a tannin binding protein produced by some folivores in their saliva - break down tannin
what is a dominance heirachy
ranking of individuals that reflects their dominance
what is dominance
the ability to defeat another individual in a pair-wise encounter
what is the ability to defeat another individual in a pairwise encounter calledq
dominance
what is a ranking of individuals based on teir dominance called
dominance heirachy
what are the considerations of a social organisation
how much comp between male+female
how much sexual dimorphism
dietary requirement
discuss the two types of resource distribution
contest: clump/patch
scramble: even distribution
name the main types of social organisation
solitary/noyau
monogamous
polyandry
polygyny
what is solitary/noyau organisation
females and their offspring have separate territories
males attempt to enclose a territory of multiple females
low sexual dimorphism
diet evenly distributed
give examples of species living in noyau/solitary organisation
Pongo pygmaeus
orangutan
Microcebus murinus
what social organisation does orangutan live in
noyau/solitary
what social organisation does the pongo pygmaeus live in
noyau/solitary
what is a monogamous family group
a male mates with only one famele, and vv
the pairing may last for one or more breeding seasons, and both parents care for young
give example of some animals in monogamy
Tarsiers
Indri indri
Callicebus moloch
what social organisation do tarsiers live in
monogamous
what social organisation do Indri indri live in
monogamous
what is polygyny
one male, multi female
female usually provides more or all of parental care
give an example of polygynous species
Gorilla
Red howler - Alouatta seniculus
Papio hamadryas - hamadryas baboon
what social organisation does Red Howler live in
polygynous
what social organisation does Gorilla live in
polygynous
what social organisation does hamadyas baboon live in
polygynous
what is polyandy
one female mates with multiple males
the male usually provides all the parental care
which species live in polyandrous organisation
Tibetan humans
Callithrix pygmaea
Saguinus oedipus
which type of social organisation do tibetan tribes live in
polyandrous
which species live in a multi male multi female organisation
Colobus guereza
Cebus capucinus
Papio anubis
which social organisation does Papio anubis live in
multi male multi female
polygamy
what social organisation has a lot of contest comp for sexually active females and is highly sexually dimorphic
polygamy
define altruism
the cost to your fitness at the benefit of others
why is altruism a problematic,
selfish behaviours are always favourable
when are spiteful behaviours theoretically possible
if the harm to receiver > harm to actor
when can cooperative behaviour be favoured
when advantage to actor > receiver
when are altuistic behaviours favourable
NEVER
what categories of social behaviour are there
selfish
spiteful
cooperative
altruism
What is an ESS (evolutionary stable strategy)
an advantageous behaviour that confers survivorship
which type of behaviour is never favoured
altruistic- as it sacrifices your fitness
what is inclusive fitness a sum of
inclusive fitness = direct fitness + indirect fitness
what is Hamiltons Eulw
altruism is expected to evolve when rb>c
in hamiltons rule, what does b stand for
benefit to the recipient of altruism
in hamiltons rule, what does c stand for
the cost to the altruist
in hamiltons rule, what does r stand for
the coefficient of relatedness between them
what rule is rb>c
hamilton’s rule
when does altruism occur? (wrt. Hamilton’s Rule)
altruism occurs if the cost is not great and relatedness is high
what is haplodiploidy
a sex determination system in which males develop from unfertilised eggs and are haploid
females develop from fertilised eggs and are diploid
what is the system called where males develop from unfertilised eggs and are haploid, and females develop from fertilised eggs and are diploid
haplodiploidy
give an example of species living in haploidiploidy
bees
what is the highest level of organisation of animal sociality defined by
cooperative brood care
division of labour into reproductive and non-reproductive
castes
how closely related are sister workers to eachother
75%
what are the male worker bees called
drones
what ploidy level are female worker bees
diploid
what ploidy level are male worker bees
haploid
define reciprocal altruism
a behaviour whereby an organism acts in a manner that temporarily reduces its fitness, with the expectation that the other organism will act in a similar manner at a later time
when is reciprocal altruism predicted to evolve
when cost of altruism low
when the benefit to recipient is high
when there are expected repeated interactions
the penalty for ‘cheating’ is a loss of future benefits
give some examples of reciprocal altruism
cleaning symbiosis
warning calls in birds
nest protection
what are the sociobiology wars
critics didnt like the suggestion that human behaviour has a genetic component - evolnary psychology contested this
