反思达尔文

RETHINKING DARWINISM PROFOUNDLY

Ｃａｉｒｎｓ 提出，Ｌｕｒｉａ 和Ｄｅｌｂｒｕｃｋ 的波动试验只是证实了随机突变———选择留存机制，并不能否定有定向突变存在． 天然遗传工程的存在则表明，生物在进化过程中并不总是被动地承受选择，有时也会主动地改变自己的遗传结构以适应环境． 这些新成果表明，自然选择不是驱动生物进化的唯一动力． 再者，无论是定向突变还是自然选择，它们解释的都是适应性进化，而适应性进化则只是生物进化中的一种非本质形式．事实上，解释适应性进化的达尔文学说，还不能回答生物如何从低级向高级进化的问题．

Cairns suggested that the fluctuation test, which demonstrated the theory of random mutation-survival by natural selection, could not refuse that bacteria can mutate adaptively in response to a selective agent. The natural genetic engineering showed that bacteria could restructure their genome to adapt to around environment sometimes instead of passively bearing natural selection. These new achievements meant that biological evolution could be driven by other forces as well as by natural selection. Moreover, the evolution caused by natural selection or by adaption mutation, which will make the organisms adapt to the environment in which they live, is not essential. There is no direction or goal in the evolution guided by natural selection. But the evolution of organism has actually the direction, which was from simplicity to complication and from low level to high level. In fact, the question of how the evolution of organism followed the direction could not be answered by Darwin's theory.