21- Primate Social and Mating Systems Flashcards
What is a mating system
Describes the way that individuals obtain and bond with mates
What is monogamous family units
- Long term pair bond
- Male and female (with offspring) jointly defend territory
What is Polyandry
- Very rare
- Several males bonded to one female
What is Polygyny
- Most common
- Multiple females per male
- Within multimale-multifemale groups
Characteristics of primate social groups
- Complex social organisation
- Variety of long-term social relationships
What are some features of primate groups
- Dominance hierarchies
- Appeasement & reconciliation after fights achieved
Evolutionary increases invocal repertoire size among non-human primates were associated with
Evolutionary increases in group size and extent of social bonding
Most common for which primates to inherit the dominance rank
Female
Rank may be dependent on
Forming alliances with other individuals
Chimps and humans share
96% of their DNA sequence
Traits of chimps
- Long-lived (c. 50 years)
- Large brains (large relative brain size and neocortexratio)
- Very fluid social organisation
- Hunt for meat
How do female and male chimps differ in adolescents
Females disperse as adolescents while males stay in natal communities throughout life
Tai Forest (Ivory Coast) by Boesch& Boesch-Achermann Chimps complex social system
- Live in communities (around 60 individuals in Tai forest communities)
- Group members gather in unstable temporary groups (parties) that usually include only a small subset of the whole community; mixed sex
- Adult males form coalitions with relatives & non-relatives
- High association rates between particular adult females –non-relatives –‘friendships’
Chimps have high level strategies for
- Aggressive interactions silent patrols. males appear to actively search for signs or presence of neighbours by patrolling alongside or within their territories
- Sophisticated ‘collaborative’hunts with hunters. Performing complementary roles all directed towards the same prey
In Tai Forest chimps how many tools are used a day
2
Tool use thought to be uniquely human till 20th century
Cultural variation in tool use for chimps
Tool use occurs in all studied populations of chimps but crucially the size and nature of the tool repertoire varies between populations, as does the toolkit
In cultural evolution inter-generation transmission of behaviour occurs through
Social learning (rather than genetically)
Chimps are unusual in that
They show cultural variation in a range of behaviour patterns
Whiten et al. 1999
Cultural differences in chimps example
- Rain dance
- Hand clasp
- Leaf napkins
- Ant dipping
Chimps and Humans are similar at
- Complex fission-fusion social system
- Elaborate strategies in territorial behaviour
- Ability to make and use tools in unusually diverse and flexible ways
Chimps and Humans difference
Human language