Chapter 8 book (exam3) - Chris Flashcards
signal
specially evolved message that contains info
honest signaling
both sender and receiver obtain a fitness benefit (+/+)
deceitful signaling
when a sender uses a specially evolved signal to manipulate the behavior of receiver so that sender receives fitness benefit while receiver pays fitness cost (+/-)
eavesdropping
sender pays fitness cost, receiver gets fitness benefit (-/+)
cue
incidental transfer of info (unintentional)
eavesdropping involves ___ NOT ___
cues NOT signals
stable info
species identity, sex, toxicity, etc.
info transfer
critical because it can directly influence fitness of both sender and receiver
i.e. honey bee dances done by foragers - and directed toward other workers about food sources
dances done by bee foragers:
A) round dance - when?
B) waggle dance - when?
A) round dance = food w/in 50 meters
B) waggle dance = food over 50 meters away.
The longer the dance the farther away the food.
Bee waggle dance - how can you tell the direction to the food source?
measure the angle of the waggle run with respect to the verticle.
Bee walks UP the comb - flowers will be found by flying TOWARD sun.
Bee walks DOWN the comb - flowers will be found by flying AWAY from Sun
Bee’s directional reference outside the hive
SUN
Vervet monkey alarm calls
advanced
pre-existing traits hypothesis
Signals evolve through senders pre-existing traits
pre-existing bias hypothesis
signals evolve through receivers preexisting biases
sensory drive
signals are fine tuned to the environment
sensory exploitation
evolution of signals that activate established sensory systems of signal receivers in ways that elicit responses favorable to the signal sender
evolution of signals that activate established sensory systems of signal receivers in ways that elicit responses favorable to the signal sender
sensory exploitation
signal that mimics the features of environmental stimuli exploits the associated receiver response
ex. light lures used by angler fish mimic bioluminescent prey of other fishes to manipulate those fish to come closer and be eaten
sensory trap
What’s this theory called?
traits providing a reproductive advantage become more common in a population over time
Darwin’s theory of descent with modification
What’s this hypothesis?
female pseudo-penis develops as a result of the exposure in utero to elevated testosterone
i. e. - pregnant hyenas
- ring tailed lemurs
extraandrogen hypothesis
i. e. pregnant hyenas have higher testosterone levels than lactating hyenas
- ring tailed lemurs have penile clitoris too; females boost concentrations of androgens in their blood at onset of pregnancy
- even when given anti-androgens - hyena daughters still have pseudo penis - just a bit altered
panda thumbs are modified wrist bones
“Panda principle” or principle of imperfection
Bee dance language could be older than _(a)___ and predate apis genus OR
could be __(b)__ when honeybees __(c)___
A) older than 40 million years
B) 20 million years old when honeybees (C) diverged from other bees
Spermatophores
packets of nutrients and sperm
hungry female mites are ____ than well fed females
more receptive to male signals
– because males release spermatophores (packets of nutrients and sperm)
males wave trembling forelegs in front of females
setting up water vibrations similar to those prey might make.
females catch males and release him unharmed
female guppies prefer
males with a particular ratio of 2 pigments (orange and red) not just orange from carotenoid content
artificial attributes elicited stronger reactions from females than
natural traits
Which came first? Trait or preference?
ex: swordtails (fish)
sensory preference for long tails (fish) must have preceded the evolution of swordtails in some relatives of X. maculatus. where male swordtail plays important role in courtship
female preference for abnormal male stimuli could be due to the fact
males are evolving quicker than females
female swordtail preference had _____ to do with swords
general preference for…
nothing to do with swords.
general preference for large males rather than sword size. swords help amplify male size.
ancient sensory bias remains unclear
what is this hypothesis?
pseudopenis not adaptive per se, but instead developed as a ______ of some other adaptive change that had positive fitness effects that may also have resulted in higher testosterone levels in females
by-product hypothesis
what is this hypothesis?
pseudopenis signals subordination or willingness to bond with others
submission hypothesis
A) what’s this hypothesis?
pseudopenis promotes formation of cooperative coalitions
B) reasons it’s not supported
A) social bonding hypothesis
B) female spotted hyenas are unusually aggressive
female spotted hyenas use anal gland secretions of other individuals to evaluate social rank
Female social rank in spotted hyenas is
extremely important
A) dominant hyena females have ___
B) dominant daughters likely to have __
A) higher reproductive success
B) higher fitness
A) Researchers suggest the need by mothers in this species to continue to help feed young after weaning led to ____
B) w/ evolution of female hierarchy may have come the evolution of a signal of __ __ - the ___
A) evolution of female dominance
B) social dominance - the pseudo penis
A) social bonding requires the willingness of dominant individuals to accept …
B) social cooperation raises…
A) somewhat lower ranking individuals as associates.
B) direct and indirect fitness of the individuals.
pseudopenis gives female a great deal of ___
control in selection of sexual partner - could contribute to maintenance of this feature.
antler size linked to
body size
male European toads can judge size of rival by
acoustic signals
some frogs use color as a
warning
in frogs male brightness did predict a male’s willingness to
initiate a fight
What’s this theory?
male threat displays should be relatively easy for large males to perform and difficult for small, weak or unhealthy males to imitate or cheat
Honest Signal Theory
Cost associated with production of an energetically expensive signal
production cost
signals that reveal information about individuals size or dominant status. usually not costly to produce but costly to maintain due to social enforcement (maintenance cost)
badges of status
dishonest signaling imposes ___ costs
maintenance costs
socially enforced signals directly influence both __ and __
reproduction and survival
use of multiple traits to signal to the same or different individuals.
i. e.
- red feathers of widow birds used in male-male encounters to establish territories
- females use tail length to make mating decisions
Multimodal signaling
A) barn swallow males communicate to males and females using song and red patches on chest. these 2 distinct signaling modalities are an example of ___
B) male son has many repeated notes which is an example of ___
A) pluripotency
B) redundancy
what’s this hypothesis?
current environment is sufficiently different from that in which the behavior evolved that there hasn’t been enough time for a species to adapt
novel environment hypothesis
p290 (spiders)
what’s this hypothesis?
the maladaptive response of the receiver is caused by a sensory mechanism that may result in fitness LOSSES for some individuals under some circumstances but does not ease the fitness gain that receivers derive on average for reacting to a sender in a particular way
net benefit hypothesis
