Which one of the following, if true, would most strengthen the position attributed to Steele and his colleagues in th...

shunhe on August 11, 2020

Hi @fable,

Thanks for the question! So we’re being asked here for what would strengthen the position attributed to Steele and his colleagues in the passage. First things first, what exactly is this position? Take a look at lines 12-16, which tell us that “[Steele] and his colleagues claim to have found evidence for a Lamarckian hereditary mechanism in the immune system.” THAT is the claim being made here, and also later on related to this, that “a virus could carry the altered DNA to the reproductive cells and replace the DNA in those cells” (lines 41-43). So (A) directly supports this position here, since that’s exactly what (A) describes.

(E), on the other hand, is incorrect because birds passing on acquired immunities to their gestating chicks via the yolk sacs in their eggs doesn’t have anything to do with altering the DNA itself, which is what the argument’s concerned with at that point in the passage. You might think that (E) strengthens Lamarck’s theory, since the theory’s about how organisms can pass on to their offspring new characteristics they’ve acquired, and (E) tells us about how birds essentially do this. But you have to distinguish Lamarck’s beliefs from the position of Steele and his colleagues. (E) strengthens the first, but not the second, and that makes it wrong for the purposes of this question.

Hope this helps! Feel free to ask any other questions that you might have.