testing hypotheses Flashcards
what are the steps of the scientific method
observation
hypotheses
predictions
tests
peer-reviewed communication
what is the difference between inductive and deductive
inductive - specific > pattern > general
deductive - existing > hypothesis > data > analyse > accept/reject
what is a scientific hypothesis
a testable statement about the relationship between two or more
variables or a proposed explanation for some observed phenomenon
two main ways to test hypotheses in evol eco
experimental comparisons between individuals
comparisons among species
example on selection pressure/adaptation
black-headed gulls - high predation risk
kittiwake - low predation risk
or
weaver birds
forests - high predation, low resources
savannahs - abundant resources
example of social structure/mating/breeding systems evolving in response to ecological conditions
ungulates
- woodland in pairs (idk-dik)
- edge in small groups (impala)
- open in herds (wildebeest)
problems/limitations of comparative studies?
alternative hypotheses
quantifying ecological variables is hard
determining causality is hard
alternative adaptive peaks
non-adaptive differences
statistical analyses and independent data
explain importance of european warblers and primate swellings
warblers - song repertoire and brain size
single/multi male mating system (evolved first) then sexual swelling (in response)
what do optimality models show
maximisation of net benefit (trade-offs)
not only test if behaviour occurs, but optimal way for it to occur
male competition for mates drives what
evolution of weaponry for mate aquisition
how can competition between males continue after mating
sperm competition
will lead to increased investment in sperm production
sperm competition experiment
horned beetles embryo cell manipulation
larger beetles, larger testes, no horns
big horns = less growth + less sperm (horns represent a substantial cost)
Evolutionary increases in horn size associated with evolutionary decreases in testes size
