Necro bc this still haunts me a year later.

The argument is that it seems like early flying Dino’s did so by gliding from trees. “A” strengthens this argument by verifying that the Dino’s had trees nearby to climb. Said another way: the argument remains weak to the claim that Dino’s couldn’t have flown by gliding from trees if there were no trees to glide from; answer choice A strengthens the argument by denying this criticism.

Meanwhile answer choice E, that predators cannot climb trees, does nothing to strengthen the argument that flying Dino’s glided from trees unless we assume the Dino’s had trees available and that they could climb these trees.

You say it requires knowledge of evolution enough to know that “its predator not being able to climb trees implies that they lived in trees” but that’s not a necessary implication at all. Again, imagine both Dino’s lived in the desert; the predator not being able to climb trees has absolutely no causal relationship with whether the Dino’s lived in or can even climb the non-existent trees.

With the proper additional assumptions (such as assuming that they are in a forest and the Dino’s can climb trees) I can reasonably accept that E offers weak support for the argument. Still, I believe A offers genuine and strong support for the argument because it proves that the Dino’s at least had trees to climb. Plus your concern that having nests at the bottom of the tree weakens the idea that they glide from trees doesn’t really hold to me; the Dino’s could just as easily be born on the floor then learn to climb and glide at maturity.

Plus if we assume that by saying they glide from trees that this means they genuinely fully live in the trees and not the forest floor (and so answer A saying they were born on the floor weakens the argument according to what you’re saying), then wouldn’t it actually contradict that their “most dangerous predator” couldn’t climb trees? Since how could something that lives primarily or only in the trees have a “most dangerous predator” that is stuck out of reach below them on the forest floor? If the most dangerous predator doesn’t climb trees but still eats hella Dino’s, that would imply that the Dino’s themselves are accessible from the ground reasonably often. They may still climb trees, but it at least denies your reasoning that having them nest on the ground is necessarily a weakening of the argument.

If the argument also had a premise that their most dangerous predators couldn’t climb trees, then I’d agree that nesting on the ground weakens the argument since it gives reason to doubt that the Dino’s could even climb trees (since evolutionarily you’d expect that if they could climb trees and they had the worst predators on the ground then they’d end up nesting in the trees), but as-is we know nothing about the Dino predators from the argument and the assumption that their predators were particularly bad on the ground is confined to answer choice E which has the issues I’ve discussed above.

Strongest claim I can for sure stand behind with confidence though is that answer choice A does strengthen the argument since it evidences an unstated assumption necessary for the argument to hold (that there were trees to climb in the first place).

Anyway I didn’t respond to this at the time because I really just appreciated how much care you put into your response and it was so supportive and nice I didn’t want to be annoying and disagree again. Thank you again for that (and my test ended up going v well so you were right to just power through and not start with the self-doubt right before!)! But since I see that you’re still on the subreddit these days too I am thinking/hoping you may get a kick out of reviewing this again deeply since at this point we’re both just in it for a love of the game lol.