Although researchers have long known that the last two interglacial periods experienced warming in the Arctic... Just beyond the northwest edge of the vast Greenland Ice Sheet, Northwestern University researchers have discovered lake mud that beat tough odds by surviving the last ice age. The mud, and remains of common flies nestled within it, record two interglacial periods in northwest Greenland. Although researchers have long known these two periods -- the early Holocene and Last Interglacial -- experienced warming in the Arctic due to changes in Earth's orbit, the mix of fly species preserved from these times shows that Greenland...