Self-study
P1
Until recently, many biologists believed that invertebrate "schools" were actually transient assemblages, brought together by wind, currents, waves, or common food sources. █████████ ██████████ ███ ████████ ██████ ██ █████████ ██ ██████████████████ ██████ █████ █████ ███████ ███ ██████ ██████ ███ ████ ███ ████ ████ ███
Biologists' old perspective ·
"Schools" of invertebrates are are not really schools
Example: groups of jelly fish are not cohesive social units that are evenly spaced from each other and face the same way. (Seems like we get a definition of "schools" here.)
New perspective ·
Some invertebrates do form schools
Example: krill (a type of invertebrate crustacean) sometimes group together in schools.
P2
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Support for new perspective ·
Groups of invertebrates can position themselves in a way that meets the definition of "school"
The way each member swims is consistent relative to other members, and they don't swim directly above or below a neighbor. (This sounds similar to the "evenly spaced" requirement.)
P3
Researchers' assumption ·
Researchers assume schooling has benefits
Concession ·
Schooling seems like it'd make animals more visible and attractive to predators
Benefits of schooling ·
Reduces chance of being eaten
School is harder to find, can scare away predators, and an individual member is more likely to get away, since there are a lot of other school members to eat.
P4
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Additional benefits ·
Active defense mechanisms
These are more active defenses, whereas the last paragraph described passive benefits. Schools have different approaches based on the size of predators and whether they are attacking.
P5
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Another benefit ·
Helps with finding food
When one member finds food, other members can follow.
Cost of schooling ·
Schools can get too big
Too many members may hurt ability to get food and mates. If school's too big, some members will join another school.
Passage Style
Phenomenon-hypothesis (RC)
Single position
6.
It can be inferred from ███ ███████ ████ ██ ███████████ ████ █████████ ██ █ █████ ██████ ██ ████████████ ██ ██████████ ██████████ ████████████ ███ ██████ █████
a
try to stay ██ ███ ████ ██ ███ ██████ ██ █████ ██ ██████ ████
This is mentioned as a behavior that some “mysids” engage in when there is intense competition within a school for food. But this isn’t connected to cannibalism, which is presented as a separate behavior resulting when food is “locally scarce.” It’s not clear that the mysid example involves what results when food is “locally scarce.”
b
be more likely ██ ██ █████ ██ ██ ████ █████ █████
If anything, this is anti-supported, because the only reference to cannibalism
c
be unlikely to ████ ████ ██████████ ██████
d
try to follow ██ ███ ████ ██ ███ ██████ ██ █████ ██ ██████ █████████
Moving to the back to escape predators isn’t mentioned as a potential behavior of an animal faced with a large school that practices cannibalism.
e
try to confuse ██████ ███████ ██ █████████ ███████ ████████ █████████
Complex swimming maneuvers aren’t mentioned as a potential behavior of an animal faced with a large school that practices cannibalism.