Reading comp PrepTest 127 · Section 4 · Question 15

Topic: Science

Paragraph 1

• Paragraph note
  • A question (why do organisms recognize kin?) and one answer (inclusive fitness theory: help relatives to increase genetic representation)
• Views, minor Meta-Structures, and the author's attitude
  • Inclusive fitness theory proponents' view:
    • Organisms pass on genes through offspring and relatives, so recognizing kin allows the organism to help its relatives and increase its genetic representation (fourth and fifth sentences)
  • Comparison, according to the author:
    • Traditional evolution says that natural selection favors individuals that produce the most offspring, while inclusive fitness theory says that natural selection favors organisms who help their relatives (fifth sentence)
    • But in both cases, natural selection favors these individuals because they increase the organisms' total genetic representation (fifth sentence)
  • Example of phenomena inclusive fitness theory has helped explain, according to the author:
    • The evolution of the honeybee and other social insects, most of which do not produce offspring (last sentence)
  • Author's attitude: "helped to explain previously mysterious phenomena" (last sentence)

Paragraph 2

• Paragraph note
  • Inclusive fitness theory applied to mysterious cannibal behavior (spadefoot tadpole example, who can become cannibalistic but avoid kin, unless really hungry)
• Views, minor Meta-Structures, and the author's attitude
  • Author's view:
    • Inclusive fitness theory has been useful in explaining findings on cannibalistic behavior (first sentence)
  • Example of application of inclusive fitness theory to cannibalism, according to the author:
    • Spadefoot toad tadpoles can become cannibalistic but only eat nonrelatives (unless really hungry) (third through last sentences)
  • Cause-and-effect relationships, according to the author:
    • A spadefoot tadpole eating a shrimp or another tadpole causes the tadpole to become larger and entirely carnivorous (fifth sentence)
  • Author's attitude: "applied usefully" (first sentence); "obvious" (second sentence); "suggests" (seventh sentence); "offers at least a partial answer" (seventh sentence); "Interestingly" (last sentence); "apparently" (last sentence)

Paragraph 3

• Paragraph note
  • Alternative answer (avoiding bacteria, tiger salamander larvae example)
• Views, minor Meta-Structures, and the author's attitude
  • Author's view:
    • Some organisms, like the tiger salamander, may recognize kin to avoid deadly diseases (first and last sentences)
  • Example of an organism that recognizes kin to avoid deadly diseases, according to the author:
    • Tiger salamander larvae sometimes become carnivorous; a deadly bacterium spreads more easily among relatives, so it's safer to eat nonrelatives (second through fourth sentence)
  • Author's attitude: "may be other reasons" (first sentence); "suggests" (fourth sentence); "may favor" (fourth sentence); "can be explained simply" (last sentence)

Main Point: The inclusive fitness theory can explain some instances of kin recognition, but alternative explanations seem to fit other organisms better.

Question/Answer: This passage best fits the Question/Answer Meta-Structure.* In such a passage, the author poses a question early on and uses the rest of the passage to answer that question. That's what this author did. The author asked why so many organisms are able to recognize their kin, irrespective of how complex that organism is. The author provides two possible answers: the inclusive fitness theory and the ... well, the second one isn't given a name, so we'll call it the don't-eat-your-kin-and-die theory.

When a passage uses a Question/Answer Meta-Structure, the main point is generally the answer the author agrees with. The author is open to both answers in this passage (though the author comes just short of fully endorsing either), as the author suggests that both explanations may apply to different organisms. So, we made sure our anticipated main point reflected the author's noncommittal stance.

*That said, you could definitely call this a Phenomenon/Explanation. After all, there is considerable overlap between the Question/Answer and Phenomenon/Explanation Meta-Structures. The author called the issue of kin recognition a "question" in the first paragraph (P1, S2-S3), so we went with Question/Answer. If you went with Phenomenon/Explanation, you'd wind up with the same understanding of the passage's organization and main point.

Example: There are two major examples in this passage, making the example the most prominent minor Meta-Structure in this passage. In fact, at least one example is provided for each explanation of kin recognition. The inclusive fitness theory is explored through the second half of the first paragraph and the second paragraph, both of which have an example (bees/social insects in the first paragraph, cannibal tadpoles in the second paragraph). The "self-preservation" explanation is presented in the third paragraph via an example of a tiger salamander larva. We should expect a few questions on these examples.

There were a lot of details and a lot of science in each paragraph, so we're going to have to rely heavily on the passage's language to help us with the more technical questions. It will be important, therefore, to know what type of information is in each paragraph so that we can quickly orient around the correct one for each question. So, we'll rely heavily on our notes for this passage.