People have long been curious about the history of life on the earth-how many different species have existed, when they first occurred, how they evolved over geologic time, and how they reacted to major environmental ...People have long been curious about the history of life on the earth-how many different species have existed, when they first occurred, how they evolved over geologic time, and how they reacted to major environmental crises.展开更多
文摘People have long been curious about the history of life on the earth-how many different species have existed, when they first occurred, how they evolved over geologic time, and how they reacted to major environmental crises.
