5: avoiding predation Flashcards
what is adaptation? in what 2 ways may it arise?
heritable trait that enhances fitness of its bearer
- by current benefits
- by past benefits and evolutionary history
is every factor that reduces predation an adaptation against predation?
no
list the 3 main ways that not all behaviours/current traits are adaptive
- trait adaptive to past conditions that no longer exist
- trait may be an incidental maladaptive side effect of another adaptation
- not yet evolved to a recent change in the environment
why may a trait being adaptive to past conditions make it non-adaptive + 2 examples? (3)
- persists as there is insufficient time/appropriate mutations to prevent the replacement of the trait
- some arctic moths fly where are no bats but will stop locomotion when exposed to experimental ultrasonic stimulus
- arctic ground squirrels live where no snakes but if exposed will respond how other squirrel species do that live in the range of predatory snakes
how may a trait being a maladaptive side effect of another adaptation prove to be non adaptive? + examples (4)
- may be genetically linked to another with a selective advantage
- the drive to care is preferentially for offspring
- female rodents in communal nests may give milk to offspring that isn’t their own due to strong parental drive
- stepparents may more likely abuse children even though it reduces their own fitness
what did Kruuk 1964 predict for mobbing in nesting gulls?
- what did he measure?
if mobbing intruders is a behavioural adaptation against egg predators then it should reduce egg predation
- measured mobbing and egg predation
what did Kruuk 1964 discover about mobbing on crows?
mobbing greater inside the colony so the egg predation is less on the inside as mobbing works to lower predation and increase reproductive success
what is the comparative method and when is it used? (4)
- method to test evolutionary hypotheses by comparing different taxa
- to see if 1 factor causes another by seeing
- if presence/absence of 2 factors is correlated
- correlate occurance of traits with benefit of trait
if mobbing is an adaptation then when would we only expect to see it?
only where effective or necessary
mobbing isnt needed in cliff dwelling gulls
- what was found because of this?
no mobbing of ground predators in cliff nesting kittiwakes on ground intruders
in the gull phylogeny what is derived and which species lack it/do mob?
cliff nesting
kittiwakes lack mobbing behaviour
all ground nesting gulls mob
in swallows some species have lost mobbing over evolutionary time- why is this and what species?
the traits are derived within their phylogeny and group
- solitary nesting rough winged swallows
what is the evolution in the loss of mobbing from the ground nesting ulls to kittiwake, from colonial nesting swallows to rough winged and between kittiwakes and rough winged swallow?
divergent
divergent
convergent
what are the 4 main anti predator adaptations?
anti-detection
anti-attack
anti- capture
anti-consumption
what is the anti-detection adaptation? (5)
- crypsis: hiding from prey
- camouflage such as mantidactylus frog looking like dead leaves
- transparency such as ribbon eel larvae
- nocturnality
- subterranean living
what is the anti-attack adaptation? (6)
- protects animals detected by predators
- springbok will stot
- selfish herding
- mimicry and warning colouration
- stinging nettle slug caterpillar has toxic spines
- horned lizard squirts blood from its eyes which is noxious to dogs
what is the anti-capture adaptation? (6)
- once predator is attempting to catch they prey
- vigilance
- run, swim , fly fast
- grasshopper jumps
- body part autonomy
- northern alligator lizard sheds its tail in response to capture attempt
what is the anti-consumption adaptation? (5)
- fighting back
- releasing noxious chemicals
- faking death
- being hard to swallow
- porcupine puffer fish inflates with water and its covered in spines so is difficult to eat
what do selfish herds reflect?
counterintuitive logic
what is the camouflage in the peppered moth?
Biston betularia
- 2 subspecies: light typica form and dark carbonaria form
- white form camouflaged in trees covered in lichen
- larvae are camouflaged to look like twigs
what are 2 important things to remember about camouflage?
- may involve any of the senses, not just vision, such as olfaction
- either or both prey and predator may be camouflaged
how did Pietrewicz and Kamils study involving blue jays test camouflage? (4)
- operant conditioning of blue jays to respond to white underwing moths
- detected fewer head up white moths on light bark, particularly those with wings upwards
- orientation important for detection
- behaviour of moths affects the ability of bird to detect them and their predation risk
what do decorator crabs do to hide from predators?
pile algae, coral, anemone on their backs and allow them to grow
in decorator crabs when tested on in a predatory fish area what was found to be the prefered choice of species to grow?
Dictyota menstrualis
5 times less likely predated if grow the prefered algae
- it contains chemical that is toxic to omnivorous fish
