chapter seven: evolution of feeding behavior

Question 1

how do crows collect and eat whelks

Answer 1

they grab one, fly up, drop it, and then repeat this process until the whelk breaks

Question 2

three observations on how these crows forage

Answer 2

1. crows choose whelks that are 3.5-4.5 cm long
2. they flew up about 5m to drop whelk
3. they kept flying up and dropping the whelk until it broke

Question 3

three predictions about crows based on these observations

Answer 3

1. large whelks should be more likely to shatter than small ones after a drop of 5m
2. 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
3. the probability that a whelk will break should be independent of the number of times it has already been dropped

Question 4

zach found that the highest net return for these crows occurs when ___ whelks are dropped from a height of ___

Answer 4

large
5 meters

Question 5

are the crows behaving optimally

Answer 5

yes

Question 6

when animals don’t appear to be behaving optimally, ____

Answer 6

other things must also factor into our explanation. animals ALWAYS behave optimally

Question 7

dugongs prefer to eat ___ but switch to ___ when ____

Answer 7

roots
leaves
sharks are around

Question 8

___ change when sharks are present in the area

Answer 8

costs

Question 9

why is it beneficial for dugongs to eat leaves when sharks are around rather than roots

Answer 9

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

Question 10

the strategy that ays off is dependent on what other individuals are doing

Answer 10

game theory

Question 11

an individual is born with one phenotype and they have that phenotype for the rest of their life

Answer 11

hereditary strategy

Question 12

cichlid fish feed by ____

Answer 12

biting the scales off of other fish

Question 13

two phenotypes are available to cichlid fish: ___ or ___

Answer 13

jaw angled to the left or to the right

Question 14

angle of the cichlid fish jaw is ___

Answer 14

hereditary

Question 15

an individuals behavior depends on what is most beneficial in the moment; individual flexibility

Answer 15

conditional strategy

Question 16

some ruddy turnstones will eat in the ___ rather than ___, why?

Answer 16

mudflats
an area with lots of food
less competition

Question 17

behaviors that are so weird that it’s difficult to make sense of their adaptivity

Answer 17

darwinian puzzles

Question 18

what is the benefit of drinking alcohol

Answer 18

could have been to know when fruit was ripe

Question 19

why is alcohol consumption problematic for some people? should we not be adapted to consume it?

Answer 19

because of the sheer volume available; the amounts in fermented fruit are minuscule compared to what we experience today

Question 20

what is the benefit of spices

Answer 20

antimicrobial

Question 21

which cultures tend to use more spices and why

Answer 21

those based in hot climates; more microbes grow in hot climates

Question 22

why do these spices only grow in hot climates

Answer 22

their antimicrobial properties are a self defense mechanism (plants are also attacked by bacteria), we simply take advantage of them too

Question 23

eating non-nutritional things (dirt, ice, soap)

Answer 23

pica

Question 24

pica could be due to ___ or ___

Answer 24

nutrient deficiencies or toxin processing

Question 25

honeybees have a language that is ___ and ___

Answer 25

precise and symbolic

Question 26

honeybees dance to convert information about ___

Answer 26

location of food

Question 27

if the food is close to the hive (< 50m), the bee performs a ___; ___ may also give another clue

Answer 27

round dance
odor

Question 28

if the bee is outside the hive, the direction of the waggle points ____ and the duration of the waggle represents ___

Answer 28

directly toward the food source
how far away the food is

Question 29

if the bee is inside the hive, bee dances on ___

Answer 29

vertical wall

Question 30

angle of the waggle relative to the vertical indicates ____

Answer 30

direction of the food relative to the sun

Question 31

a possible first stage of the dancing behavior

Answer 31

trigona bees

Question 32

trigona bee behavior

Answer 32

returning foragers hum and mov excitedly; other foragers smell bee and go search for that food

Question 33

food for these trigona is ___ because they live in the tropics

Answer 33

never far

Question 34

some trigona make ___ to food

Answer 34

scent trails

Question 35

melipona bees make ___

Answer 35

sound pulses

Question 36

the longer the pulse, the ___ the food

Answer 36

further

Question 37

melipona discoverer makes several short zig zag flights to indicate ___

Answer 37

direction of food

Question 38

Apis florea dances on ___, waggle ____

Answer 38

horizontal comb in the open
points directly to food

Question 39

Apis mellifera (honeybee) has the ____ language

Answer 39

most complex

Question 40

if a behavior is adequate, there is no ____

Answer 40

selective pressure to improve