Even some ardent conservationists acknowledge that the diversity of life on earth cannot be fully sustained as human populations expand use more resources nudge the climate and move weedlike pests and predators from place to place 连一些积极的自然资源保护论者都承认，随着人口的膨胀、消耗更多的自然资源、引起气候的变化，以及造成大量害虫和捕食动物的迁移等，地球上的生物多样性肯定不会完全地持续下去。
