Final Flashcards
3 methods of hypothesis testing
- observational
- experimental
- comparative
At what level is the intensity of natural selection highest?
The individual
cross generational, evolutionarily determined behaviour via natural selection and descent with modification
Ultimate causes of behaviour
Neural-hormonal mechanisms developing within an animal in its lifetime
proximate causes of behaviour
When communication signals exploit existing sensory abilities and biases in the receivers
sensory exploitation
Due to processes such as sensory exploitation, the result is not always ideal but is functional
Principle of Imperfect (Panda principle)
Signals communicated to rivals that accurately display its dominance potential
honest signal hypothesis
What support is there for the honest signal hypothesis (why wouldn’t there be more fakers?)
faked signals would be devalued by their commonality. species often check for cheaters, selecting for accuracy.
Predators that mimick mating calls of other species to lure them.
illegitimate signallers
why do prey fall victim to deception? (2)
- Novel environment theory: there has not been enough time to adapt and overcome
- Net benefit theory: the gains this behaviour provides outweigh the losses.
predators that use their prey’s signals to locate them
illegitimate receivers
the theory that there is no such thing as purely environmentally determined behaviour, nor purely genetically determined behaviour
The interactive theory of development
- environmental factors influence which genes are active
distinct yet coexisting phenotypes that allow for individual flexibility
polyphenisms
learning to associate a voluntary action with the consequences that follow
operant conditioning
behaviour that is not learned by imitation or trial and error. May be modified by experience
innate behaviour
where is innate behaviour most advantageous?
in predictable environments where a reliable relationship between cue and response exists.
in what environments is learned behaviour advantageous over innate behaviour?
unpredictable ones.
what are the 3 main processes of the nervous system?
- input of info from outside via the senses.
- integration and processing of info
- output of appropriate activity
What are two important features of the nervous system?
- incoming info is filtered and sorted
2. incoming signals may be inhibited by other neighbouring impulses to ensure priority.
the study of proximate and ultimate causes of animal behaviour
ethology
behaviour pattern that appears fully functional from the first time it is performed. dependent on gene-environment interactions.
instinct or Fixed Action Pattern (FAP)
the stimulus that activates a Fixed Action Pattern
an innate releasing mechanism
the exploitation of fixed action patterns by other species
code breaking
the ability of neurons and neural networks to filter or ignore information that is irrelevant
stimulus filtering
neural clusters that play a preprogrammed set of messages to organize motor output
central pattern generators
The bias in the somatosensory cortex towards senses more vital to survival and reproduction
cortical magnification
A reproduction strategy that results from females living in dense clusters. usually a defence mechanism from predators.
Female defence polygyny
a reproduction strategy in which a male usually controls a rich resource
resource defence polygyny
Explain the polygyny threshold hypothesis
a female may choose polygyny, even at the risk of lower reproductive succcess, because it may be too costly to find another mate or another mate may have poor territory.
reproductive strategy in which large territories are too costly to defend and resources or females are sparse
scramble competition polygyny
reproductive strategy where males do not search for mates, but might fight for a small display arena. Huge mating inequalities.
lek polygyny
what are 3 possible benefits to lek polygyny?
- hotspot hypothesis: males congregate at well-trafficked areas of females.
- hotshot hypothesis: subordinate males congregate around dominant males
- female preference: females prefer clusters of males.
3 reasons why traits may not be perfectly adaptive:
- failure of appropriate mutations to occur
- pleiotropy - gene has multiple effects, some positive, some negative
- co-evolution - arms race.
testing predictions about whether or not other species will exhibit a trait.
the comparative method.
so much prey that the predator is overwhelmed
the dilution effect
individuals are treated as game participants, whose success is dependent on rival’s behaviour
game theory.
animals group together for individual benefit, aiming for a central position
selfish herd theory
method used to quantitatively determine value of traits. adaptations have greater benefits-to-cost ratio than the alternatives that have been replaced via natural selection
optimality theory
where two phenotypes coexist because as one declines the other becomes more advantageous and vice versa, reaching an equilibrium
frequency dependent selection
the ability to be flexible. higher ranking individuals may get to chose their strategies while lower ranking individuals must settle for what’s left.
conditional strategy
when individuals are free to distribute themselves in relation to resource quality and intensity of intraspecific competition, there is a point where an individual can gain a fitness advantage by choosing a lesser value, but more sparsely occupied habitat
ideal free distribution theory
a strategy that cannot be replaced by an alternative
evolutionarily stable strategy
contests between ex-residents and replacements intensifies as absence is extended. newcomers become more familiar with their territory and site value to them increases
payoff asymmetry hypothesis
when individuals expend less energy intimidating familiar neighbouring rivals
dear enemy effect.
1 male for multiple females
polygyny
1 females for multiple males
polyandry
under what two conditions is monogamy favourable to males?
- if the mate remains receptive after mating
2. the male’s chance of finding another mate is low
reproductive theory in which male helps female and this sacrifice is compensated by more offspring produced
mate assistance hypothesis
2 examples of sexually monopolizing partners
- mate guarding hypothesis
2. female-enforced monogamy
under what conditions does monogamy occur in mammals?
when females are sparsely populated in small territories (easy for males to guard)
under what conditions is polyandry common?
a shortage of suitable territories and a limited number of females . in some species the female can’t adequately care for more than 4 eggs, so it’s beneficial to have multiple clutches with multiple partners.
what are 3 genetic/indirect benefits of polyandry?
- Fertility insurance hypothesis: secures females against the possibility of an infertile mate
- good genes hypothesis: offspring from multiple partners may have a better chance of survival
- genetic compatibility hypothesis: increased genetic variety boosts chance of female receiving unusually compatible genes.
what are 4 material/direct benefits of polyandry?
- more resources hypothesis: partners supply resources to the female
- more care hypothesis: more partners = more caregivers
- better protection hypothesis: more protectors from harassment
- infanticide reduction hypothesis: more uncertainty about paternity = fewer males with no stake in offspring survival
explain sexual selection theory
solution to why extravagant courtship behaviours have developed. although behaviour seems costly, increased reproduction must compensate for likely shorter lives.
explain the sexual differences theory
males compete for females, because of supply and demand. there are many more eggs than sperm, therefore female reproductive success is limited by number of eggs produced not number of mates. quality versus quantity.
why are females more likely to exhibit parental care?
more care equals greater chance of survival, but less ability to produce more offspring (numbers game). a male might miss reproductive opportunities. males can’t be assured offspring are truly theirs.
ratio of sexually active males to sexually receptive females
operational sex ratio
what types of species are more likely to exercise parental care, why?
short-lived and therefore low reproducing, species. longer-lived species have more chances to reproduce in their lives.
why do males exhibit parental care?
if they can care for more eggs than females can produce, then care behaviour is more costly to females, and a male must defend a territory anyways.
individuals donate help when others need it, in exchange for help when they need it themselves
reciprocal altruism
a social interaction where both directly benefit immediately
cooperation
a social interaction where one individual directly benefits immediately and another directly later
postponed cooperation
a social interaction where one individual directly benefits, and the favour is returned to another individual later
reciprocity
When the frequency occurrence of a helpful gene increases rather than decreases as a result of altruistic behaviour
inclusive fitness rule
The explanation for why extravagant courtship behaviours have evolved.
sexual selection theory
why do males compete for females and not vice versa?
sexual differences theory. Many more sperm exist than eggs (supply and demand). female reproductive success is limited by number of eggs produced, not number of mates, so quality is more important than quantity.
why does adoption occur?
costs of caring for other’s offspring outweighs costs of potentially rejecting own offspring.
what is the mafia hypothesis?
that parasite parents may seek revenge if they return to find their eggs harmed
what is the gradual shift hypothesis?
the theory that brood parasitism developed gradually, with species first parasitizing intraspecifics, possibly those that shared nests. Supported by the fact that species new to parasitism target similar species.
why do parents show favouritism?
they might be targetting those that need care the most (females) or those most likely to succeed (first hatched). Sometimes resources are directed to those that can produce the most offspring.
why do some parents allow siblicide?
the brood eliminates the weak, allocating limited resources to those likely to survive, therefore saving the parents time and energy.
