摘要
Two million years ago,in what is now the icy barren tip of northern Greenland,mastodons,reindeer,rodents,and geese roamed through forests of poplar,spruce,and birch.The existence of that surprisingly lush ecosystem is one conclusion of research reported in a December 2022 Nature paper in which an international team of scientists sequenced 2-million-year-old plant and animal deoxyribonucleic acid(DNA)isolated from frozen sediment samples[1].
