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.)
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.)
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.
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.
Passages that focus on describing or evaluating potential explanations for a given phenomenon. Causal reasoning features prominently in these passages.