灭绝|4亿年前的绿色凶手，主导了一次生物大灭绝( 四 ) 地球|奥陶纪

那么回头看5亿年前刚刚从水中探出点点绿色的植物，是否有人能想到它们可以改变千万年后地球的海洋生物世界呢？

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英国地质学家T. M. Lenton在国际地学学术期刊Nature Geoscience上发表的论文将奥陶纪末大冰期罪魁祸首的矛头直指陆生植物（图片来源：Nature Geoscience）
不过，我们大可不必对身边的花花草草这么苛刻，毕竟导致一次席卷全球的生物大灭绝事件的诱因往往不止一个。即使它们真的是第一次生命大灭绝的凶手，我们也不能否认这些先驱者的功绩，正是它们的成功登陆，才为后来繁华的陆地生物圈开拓了新的舞台。
在第一次生命大灭绝结束后的两亿年中，它们不仅继续参与对地球大气圈氧气含量的调节，使之更加适宜生物生存，也制造了更多的土壤。更重要的是，它们为后来的陆生生物的多样性和大体型提供了物质基础，可谓是真正的前人栽“树” ，后人乘凉。
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