转基因作物,支持or反对?

1996年到2007年,全球转基因农作物种植面积累计达到6.9亿公顷,12年间转基因农作物种植面积增长了67倍,推广应用速度之快出乎人们意料. 目前全球基因作物种植面积的前四名分别是美国、阿根廷、加拿大和中国.这四个国家种植了全世界99%的转基因作物.     

Paleontology. Feathers, or flight of fancy?

On page 2202, researchers describe the 220-million-year-old Longisquama insignis, a squat, mouse-sized reptile with at least six vanelike appendages up to 12 centimeters long sprouting from its spine. The authors argue that the appendages are feathers much like those of modern birds; outside the paper, they have touted the fossil as "an ideal bird ancestor." That conclusion has infuriated paleontologists--not just because it challenges the prevalent theory that birds evolved from theropod dinosaurs, but because they say it does so in an unscientific way.