Self-study
P1
Mechanisms for recognizing kin are found throughout the plant and animal kingdoms, regardless of an organism's social or mental complexity. ████████████ ██ ███ ███████ █████████████ ██ █████ ██████████ ████ ██████ ████ ███████████ █████████ ██ ███ ████████ ██ ███ ███ ███████████ ██████ ██ ████ ███
Phenomenon ·
Many plants and animals can recognize "kin" (relatives)
Inclusive fitness hypothesis ·
Organisms transmit genetic material through relatives (not just offspring)
Contrast inclusive fitness with traditional view of evolution. Under traditional view, natural selection favors those with the most offspring. Inclusive fitness suggests natural selection also favors organisms who help their relatives (because this helps spread the organism's own genes).
Inclusive fitness applied ·
Helps to explain why social insects like bees evolved
P2
█████████ ███████ ██████ ███ ████ ████ ███████ ████████ ██ ███ ████████ ██████████ ███████████ ██████ ██████ ████████ █████ ██ ███ ███████ █████████ ██████ ████ ███████ ██ █████ ██████ █████ ███ ███ ███████ ██ ███ ███████ ███████ █████ ██ ████ █ █████████ ███
Inclusive fitness applied ·
Theory predicts that cannibals will avoid eating their own relatives
Example of theory applied to cannibals ·
Spadefood toad tadpoles
Some tadpoles eat their own species. But they nip at other tadpoles before eating, and end up eating only nonsiblings. Suggests they're trying to avoid eating their kin. But, they're more likely to eat kin when they're very hungry.
P3
███ █████ ███ ██ █████ ███████ ███ █████████ █████████ ████ ███
Other explanations for kin recognition ·
Inclusive fitness theory isn't the only explanation
Example showing other explanation ·
Tiger salamander larva
Some larva are cannibals. The bacteria are more deadly to close relatives, because the relatives have a similar immune system to the infected larva. So, when tiger salamanders avoid eating their close relatives, it could be because they just don't want to die from the bacteria in their relatives. This is about the organism's individual self-interest, not about trying to increase overall genetic representation.
Passage Style
Phenomenon-hypothesis (RC)
Single position
11.
Which one of the following ████ ██████████ █████████ ███ ████████ ██ ███ ████ ████████ ██ ███ ██████ ██████████
a
to draw attention ██ ████████ ████ ███████ ███████████ ███ ███ ██ █████ ██ ██ █████████ ██ ███ ██████ ██ ███████ █████████ ████ ████████ ███ ███ ███████████
This is the best answer. The last sentence of P2 presents an interesting behavior observed in cannibal tadpoles. Sometimes they do eat siblings, even though other times they don’t. This is a fact that an explanation of kin recognition will have to take into account. Whether we propose inclusive fitness theory or something else to explain the cannibal tadpole’s behavior, our explanation will need to address why the tadpole sometimes eats its siblings.
b
to explain why █████████ ██ ████ ███████ ███ █████ ███ ████ █████ ████ ██ ████████ █████████ ████ ████████
The author doesn’t provide any evidence concerning the behavior of cannibals in “most” species. So (B) wouldn’t make sense as the author’s purpose.
c
to describe behavior ████ █████ ███████ ██ ███ ███████ ██ ███ ███████████ █████████ ██ ███ ██████ █████████
Although the rest of the discussion of tadpoles supports the author’s account of kin recognition (inclusive fitness theory), the sentence we’re asked about does not. It contains an example that shows sometimes a tadpole will still eat its siblings, which isn’t something inclusive fitness theory would predict.
d
to offer evidence ████ ███ ████████ ██ ████████ █████████ ████ ████████ ██ █████████████
This can’t be the purpose, because the author does try to offer an explanation of the cannibal tadpole behavior. The rest of the discussion in P2 shows that the author believes inclusive fitness theory can explain the behavior. Although there is a certain kind of behavior that inclusive fitness theory doesn’t necessarily explain, this doesn’t imply that it’s impossible to explain the cannibal tadpole behavior.
e
to imply that ███ █████████ ████████ ██ ████ ████████ ██ ███ █████ ██ ████ ████ ██ ███ ███████████ █████████ ████████
The author doesn’t suggest that the last sentence of P2 is more relevant than the previous discussion in P2. In fact, the previous discussion in P2 shows how cannibal tadpole behavior in general can be explained by inclusive fitness theory. That discussion is equally or more relevant than the behavior described in the last sentence, because the author’s overall point in the passage is to show how inclusive fitness theory can explain at least some instances of kin recognition.