chapter seven: evolution of feeding behavior Flashcards
(40 cards)
how do crows collect and eat whelks
they grab one, fly up, drop it, and then repeat this process until the whelk breaks
three observations on how these crows forage
- crows choose whelks that are 3.5-4.5 cm long
- they flew up about 5m to drop whelk
- they kept flying up and dropping the whelk until it broke
three predictions about crows based on these observations
- large whelks should be more likely to shatter than small ones after a drop of 5m
- drops of less than 3m should yield a reduced breakage rate whereas drops of much more than 5m should not greatly improve the chances of opening a whelk
- the probability that a whelk will break should be independent of the number of times it has already been dropped
zach found that the highest net return for these crows occurs when ___ whelks are dropped from a height of ___
large
5 meters
are the crows behaving optimally
yes
when animals don’t appear to be behaving optimally, ____
other things must also factor into our explanation. animals ALWAYS behave optimally
dugongs prefer to eat ___ but switch to ___ when ____
roots
leaves
sharks are around
___ change when sharks are present in the area
costs
why is it beneficial for dugongs to eat leaves when sharks are around rather than roots
they don’t need to have their head in the ground looking for roots when there are predators near, even though the roots are more nutritious than leaves
the strategy that ays off is dependent on what other individuals are doing
game theory
an individual is born with one phenotype and they have that phenotype for the rest of their life
hereditary strategy
cichlid fish feed by ____
biting the scales off of other fish
two phenotypes are available to cichlid fish: ___ or ___
jaw angled to the left or to the right
angle of the cichlid fish jaw is ___
hereditary
an individuals behavior depends on what is most beneficial in the moment; individual flexibility
conditional strategy
some ruddy turnstones will eat in the ___ rather than ___, why?
mudflats
an area with lots of food
less competition
behaviors that are so weird that it’s difficult to make sense of their adaptivity
darwinian puzzles
what is the benefit of drinking alcohol
could have been to know when fruit was ripe
why is alcohol consumption problematic for some people? should we not be adapted to consume it?
because of the sheer volume available; the amounts in fermented fruit are minuscule compared to what we experience today
what is the benefit of spices
antimicrobial
which cultures tend to use more spices and why
those based in hot climates; more microbes grow in hot climates
why do these spices only grow in hot climates
their antimicrobial properties are a self defense mechanism (plants are also attacked by bacteria), we simply take advantage of them too
eating non-nutritional things (dirt, ice, soap)
pica
pica could be due to ___ or ___
nutrient deficiencies or toxin processing
