what is the integrative approach in studying animal behavior? (4 approaches we are taking in this course)
- ecological approach
- mechanistic appraoch (genes, neurology, physiology)
- developmental appraoch
- phylogenetic approach
what are the 3 features of natural selection by charles darwin?
- variation - different traits in individuals
- differential reproductive success - some individuals reproduce more
- inheritance - basis for diff in trait affecting reproductive success
one feature of natural selection is inheritance:
the basis for difference in traits affecting reproductive success are based on ________ factors.
hereditary
what are adaptations?
heritable traits that benefit individual’s ability to survive and reproduce (favorerd by natural selection)
adaptations increase _____, which is a measure of reproductive success
fitness
evolution aka?
descent with modification
alleles - ________ - trait - ___________
genotype; phenotype
what is the gene-centric approach to evolution (4 steps)?
note: genes are main drivers of evolution. natural selection works on genes, not individuals or species. Genes that help organism survive and reproduce get passed on to the next generation.
- traits influence ability to reproduce
- alleles/genes supporting these traits passes on to next gen
- alleles increase in frequency in the next gen
- evolution occurs by this change in gene structure of the population
what is evolution?
evolution is:
1. change in gene frequency.
2. result of reproductive outcomes over long periods
natural selection is not evolution, but a _________ of evolution. it is also ________.
cause; unintentional
1) scientists develop hypotheses about a behavior.
_________ hypotheses are competing explanations.
_________ hypotheses are multiple explanations.
2) hypotheses make predictions about _________ r/s on fitness.
these hypotheses predict whether the fitness _______ of having the trait outweigh its _____.
If the benefits are greater, the trait is likely to be ________ through generations.
If the costs are ______, the trait might not survive long in the population.
1)
alternative
non-mutually exclusive
cost-benefit
2)
cost-benefit
benefits; costs
passed on
greater
direct vs indirect measures of fitness.
direct measures look at organism’s actual reproductive success
while
indirect look at traits that suggest reproductive success
state 3 direct and 3 indirect measures of fitness.
direct
- production of gametes
- rate of mating (copulation)
- fertilisation of eggs
- no. of offspring
- rate of offspring growth
- offspring survival to adulthood
- alleles they are carrying
indirect
- ability to survive
- ability to compete
- access to food
- access to living space
- efficiency of locomotion
- morphological/physical features
- immune response
what are the 2 levels of analysis in the study of animal behavior, and what does each contain? (tinbergen’s 4 questions)
proximate level
- development (assembly of animal, internal components)
- mechanism (neuronal-hormonal mechanisms controlling animal’s behavior)
ultimate level
- evolutionary history
- adaptive function (adaptive value as affected by natural selection)
which level of analysis is associated with male digger bees smelling the females and locating them for mating?
proximate level - mechanism
what are the 3 appraoches to study animal behavior?
- comparative (comparing behavior across diff species)
- expt
- observational
what is the predator distraction hypothesis?
by mobbing potential predators, gulls distract them from predating on their nests
which of the 3 study approaches did hans kruuk use to investigate the predator distraction hypothesis?
all 3.
- observational
- expt (placed 10 eggs every 10m, on a line from inside to outside nesting colony, and observed which eggs were predated on by the carrion crows)
- comparative (explored gull phylogeny to see if ground-nesting is an ancestral feature of seagulls, and if mobbing is found only in ground-nesting gulls)
closely related species more similar than distantly related species due to __________ contraints. (ie. similar inheritance)
evolutionary
convergent evolution vs divergent evolution
convergent evolution is whereby distantly related species share similar traits due to similar living conditions.
while
divergent evolution is whereby closely relate species have different traits due to changing conditions.
occam’s razor means _______
parsimony - simplest explanation possible
