PT127 · S1 · Q7 Two different dates have been

This sounds stronger than anything we learned. Can we say that there were no warmth-adapted beetles in areas where the predominant tree cover consisted of spruce forests? This answer is jamming the two sentences together in a way that goes beyond the "500 years" comparison we know. The first date came by studying dirt (in some area that would be cold during an ice age but warm once the ice age ended). They studied the transition from when a cold-weather species lived somewhere to when a warm-weather species started living there. We don't know if these sediment samples were from a spruce forest at all.

Just like (A), this is trying to jam together the sediment / beetle fact with the pollen grain / spruce fact, but the only means we have to compare them is the 500 year fact. This answer, like (A), is acting as though these two tests were conducted in the same area, but the paragraph never said any such thing. We have no reason to think that the beetle-test was done in the same area as the pollen grain testing, so we have no way to support that you'd find cold-beetle fragments and pollen grains in the same area.

When an ice age begins, the polar ice caps steadily advance outward from the poles (the ice caps from the North Pole extend down through Canada to the northern latitudes of America). They get as far south as the new ice age climate will allow, then they pretty much stay there until the climate starts to warm again. When an ice age ends, the polar ice caps steadily retreat backwards towards the poles. The fact that warm-beetles came out 500 years before "ice masses yielded to spruce forests" implies that when warm-beetles came back, the ice caps had not yet receded towards the North Pole. This answer, meanwhile, is saying that the ice caps were still advancing southward through North America. We have no evidence for that.

During an ice age, as the polar ice caps expand southward, the arctic habitat expands. A polar bear might end up all the way down where New York is. But when the ice age ends, the polar ice caps recede back towards the poles, shrinking the arctic habitat, forcing the cold-adapted animals to migrate back north where it's cold enough for their liking. The first date came from scientists looking at a certain area like New York that is cold during an ice age but warm otherwise, so that they could see when it went from being a place where cold beetles wanted to live to being a place where warm beetles wanted to live. The fact that warm beetles started living somewhere just means that that area because too warm for cold beetles, but that doesn't mean all cold beetles died out. Their habitat just shrunk, so they would have headed north to where it was still cold.