|
6. 北美洲大型动物已灭绝，学者建议重新引进的 P4：有人要反对了。（说以前的大型动物和现在的不像，现在的不能在这住。支持者就说根据DNA检验，可以啊（有结构题，问DNA出现的作用——就是证明它们可以在这生活；
又有人反对说现在和以前环境不一样了啊，支持者又说了（忘了） the (忘了）is :the Many have expressed concern about the fact that North America’s ecosystems are not the same today as they were 13,000 years ago and that reintroduced animals might therefore be unable to survive in them. Whereas habitats are and will continue to be dynamic on a timescale of thousands of years, very few plants or small mammals went extinct during the late Pleistocene. The major missing component of North American ecosystems today compared with the Pleistocene is the megafauna, which we can infer are critical cogs in the wheels. | 
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2009-2-10 09:16:00
