[1] In 1959, Soviet geneticist Dmitry Belyaev began a decades-long experiment to understand how wild animals become domesticated. [2] He hypothesized that selecting animals solely for their tameness would trigger a cascade of physical and behavioral changes over generations. [3] To test this, Belyaev bred silver foxes, selecting only those that showed the least fear and aggression toward humans. [4] Over several generations, the foxes not only became friendly like domestic dogs but also developed floppy ears, spotted coats, and wagging tails. [5] Silver foxes are a color variant of the red fox, *Vulpes vulpes*.
The writer is considering deleting Sentence 5 from the paragraph. Should the sentence be kept or deleted?
- AKept, because it provides necessary background information defining the specific animals that Belyaev chose for his research.
- BKept, because it supports the passage's argument by explaining why Belyaev's findings are limited to the species *Vulpes vulpes*.
- Deleted, because it interrupts the paragraph's discussion of the experiment's methodology and results with an irrelevant taxonomic detail.Answer
- DDeleted, because it contradicts Belyaev's hypothesis by suggesting that the foxes' traits were inherited from a different species.
Answer
Deleted, because it interrupts the paragraph's discussion of the experiment's methodology and results with an irrelevant taxonomic detail.
The sentence should be deleted because the paragraph focuses on Dmitry Belyaev's evolutionary experiment on animal domestication, specifically how he bred silver foxes to select for tameness and the physical traits that resulted. Stating that silver foxes are a color variant of the red fox (*Vulpes vulpes*) is an irrelevant taxonomic detail that interrupts the narrative flow of the experiment's methodology and results.
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Sentence Addition and Deletion Decisions