2006年5月24日星期三下午3点

    Biological diversity has become widely recognized as a critical conservation issue only in the past two decades. The rapid destruction of the tropical rain forests, which are the ecosystems with the highest known species diversity on Earth, has awakened people to the importance and fragility of biological diversity. The high rate of species extinctions in these environments is jolting, but it is important to recognize the significance of biological diversity in all ecosystems. As the human population continues to expand, it will negatively affect one after another of Earth’s ecosystems. In terrestrial ecosystems and in fringe marine ecosystems ( such as wetland ), the most common problem is habitat destruction. In most situations, the result is irreversible. Now humans are beginning to destroy marine ecosystems through other types of activities, such as disposal and runoff of poisonous waste; in less than two centuries, by significantly reducing the variety of species on Earth, they have unraveled cons of evolution and irrevocably redirected its course.

    近二十年”生物多样性”才被广泛认为是一个危急保护问题. 锐减的热带雨林,地球已知物种最丰富的生态系统, 唤起人类对生物多样性的重要性和脆弱性的认识. 这些环境中物种灭绝速率之快让人震撼,但重要的是认识到物种多样性在所有生态系统中的意义. 随着人口持续膨胀,它将会给地球的一个又一个生态系统带来负面影响. 在陆地生态系统和边缘海洋生态系统(比如湿地),最共通的问题是栖息地被破坏. 多数情况下,结果是不可逆转的. 现在人类又开始通过种种人类活动来破坏海洋生态系统了,比如处理和排放有毒废物; 用不了两个世纪, 通过锐减地球的物种, 人类就会揭示进化的方向并且无法挽回地改变了其轨迹.

    Certainly, there have been periods in Earth’s history when mass extinctions have occurred. The extinction of the dinosaurs was caused by some physical event, either climatic or cosmic. There have also been less dramatic extinctions, as when natural competition between species reached an extreme conclusion. Only .01 percent of the species that have lived on Earth have survived to the present, and it was largely chance that determined which species survived and which died out.

    当然,在地球历史上也有些时期发生过大灭绝.恐龙的灭绝由某些自然事件导致,气候的或是宇宙的. 同样也有非急剧性的灭绝, 即物种间的自然竞争最后付诸极端的解决方案.地球上生存过的物种只有百分之0.1存活至今,并且有很大偶然因素决定哪个物种存活而哪个被淘汰.

    However, nothing has ever equaled the magnitude and speed with which the human species is altering the physical and chemical world and demolishing the environment. In fact, there is wide agreement that it is the rate of change humans are inflicting, even more than the changes themselves, that will lead to biological devastation. Life on Earth has continually been in flux as slow physical and chemical changes have occurred on earth, but life needs time to adapt-time for migration and genetic adaptation within existing species and time for the proliferation of new genetic material and new species that may be able to survive in new environments.