Lecture 1: introduction Flashcards
the adaptationist approach:
animals life is adapted to the environment to which it lives
- natural selection
- adaptation
adaptationists examples: Social organisation of weavers
– different species of weavers live in different types of nests, some 10 pairs/tree, 100/200 nests in 1 tree, 100 of birds one nest etc
who is John Crook?
- first to take true adaptationists approach
- 1964 paper on social organisation of weavers
- lots of q to answer (sexual question/social)
- results from paper: primary drive of social organisation was FOOD (more likely to be social when feeding on grasslands seeds rather than insects)
- social organisation is a function of food supply
to complete a comparative analysis u need:
- you need to know phylogeny
- compare multiple species
- studies interspecific traits
Individual variation: Ruff:
- White headed dominant to black (most mating)
- satellite males (hang around)
- female mimics
individual variation studied between ___ a few examples
- Intraspecific traits (behavioural)
- Infanticide
- male pregnancy (seahorse)
- sexual cannibalism
long term studies of marked individuals pros and cons
pros:
-fitness consequences of behaviour
cons:
-long time (elephant similar life to human)
experimental work field example
-long tail study in window birds
study of individuals is
infraspecific variation
2 types for studying individuals
- observation in field / lab
- experimental studies
evolutionary theory:
- framework allowing us to interpret behaviours we see
- Charles Darwin: Origin of species 1850s-1870s
Ronald Fisher: 1930s-1940’s
statistician, mathematician and biologist
-how genetics work combining eve theory and mendelian genetics
Bill Hamilton 1960’s - 1990’s
& George Williams 1960’s - 1990’s
Inclusive fitness theory
–selection doesn’t work on groups but as finer level
John Maynard Smith 1960’s - 1990’s
Game theory and study of behaviour
Geoff Parker 1970-2000
sperm competitions and sexual selection
adaptationist approach includes:
- evolutionary theory
- animal behaviour
- ecology
Weigh up the COSTS and BENEFITS of a behaviour to determine its ADAPTIVE SIGNIFICANCE
WHY has it evolved?
what biological unit does natural selection act on?
GENES and INDIVIDUALS
- individuals die, survive and reproduce but consequence is that gene frequencies in population change
Natural selection acts on ____ to produce organisms that are designed to ___ their inclusive fitness
GENES, MAXIMISE
some ultra-selfish genes e.g. sex ration distorters though do exist
we expect genes and individuals to be ___ resulting in conflict
selfish
why doesnt group selection work?
any mutant selfish genes spread v v quick through population
-lemmings, water, rubber ring
3 types of conflict were studying
- sexual
- parent-offspring
- sibling
cooperation is vulnerable to exploitation, illustrated by
PUBLIC GOODS GAME
-cooperators contribute to public good, they gain benefits, BUT so do the free riders
group of cooperators outcompete
non cooperators
- non-cooperators DO BETTER than cooperators within groups
- –> temptation to defect
Tragedy of Commons
Hardin 1968,
- shared benefits or a ‘public good’ that individuals contribute to, there will be temptation to cheat or free load
- e.g. sociable weaver (large nest)
cooperation interspecific
- cleaner shrimp and fish
- giving blood
cooperation intraspecific
- worker termites and queen termites
