the adaptationist approach:
animals life is adapted to the environment to which it lives
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?
to complete a comparative analysis u need:
Individual variation: Ruff:
individual variation studied between ___ a few examples
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
- experimental studies
evolutionary theory:
- 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:
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
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
Tragedy of Commons
Hardin 1968,