The Adaptationist Approach

Question 1

Social organisation of weavers

Answer 1

Cassin’s Malimbe is solitary but the sociable weaver can have hundreds of birds in a single nest

Question 2

Why are some weavers solitary and other colonial? Why are some dimorphic and others monomorphic?

Answer 2

Depends on habitat, food availability and predation.

Forests/Insects : Solitary and monogamous

Grassland/Seeds: Social and Polygamous

Question 3

Food distribution predicts social structure in primates as well as weavers

Answer 3

This is studied by Comparative Analysis

Question 4

Comparative analysis

Answer 4

Looks at interspecific variation. Phylogenies and ecology are both very important.

Question 5

Individual variation is studied through

Answer 5

the causes and fitness consequences of intraspecific variation

Question 6

Drawbacks of long-term studies

Answer 6

Species can have long lifespans, therefore can’t collect inter-generational data easily

Question 7

Key figures in Evolutionary theory

Answer 7

C Darwin	1850s – 1870s
RA Fisher	1930s – 1940s
WD Hamilton	1960s – 1990s
J Maynard Smith 1960s – 1990s
RL Trivers	1970s…..

Question 8

The adaptationist approach looks at

Answer 8

evolutionary theory
animal behaviour
ecology

Question 9

The adaptationist approach weighs up

Answer 9

the costs and benefits of a behaviour to determine its adaptive significance. i.e. the function of a trait and why it evolved

Question 10

Natural selection acts on

Answer 10

gene frequency in a population due to survival, death, reproduction of individuals

Question 11

Natural selection tests

Answer 11

the inclusive fitness of an individual

Question 12

Conflict arises through

Answer 12

selfish genes and individuals

Question 13

Group selection doesn’t work under most natural conditions

Answer 13

Altruistic groups are vulnerable to selfish behaviour by individuals

Question 14

Family conflict

Answer 14

Male female sexual conflict
Parent offspring conflict
Sibling conflict

Question 15

Intra and interspecific cooperation

Answer 15

must face the social dilemma and temptation to defect

Question 16

The public goods game

Answer 16

Free-riders benefit more than contributors in terms of public goods when they are shared equally

Question 17

Tragedy of the commons/Prisoner’s dilemma

Answer 17

is not inevitable. mecahnisms to resolve the conflict between selfish and social cooperation are widespread in nature

Question 18

Summary

Answer 18

1. Adaptationist approach to studying animal behaviour
2. Introduction to some major players in development of core ideas
3. General expectation of selfishness and conflict because of selection at the level of genes or individuals
4. But cooperative behaviour is ubiquitous… WHY?