And their billions of descendants... 以及他们的亿万后代

75. They are a vital ancestor
    他们是从古到今所有植物
76. of all yesterday's and today's plant species.
    的关键祖先
77. These tiny bacteria...
    这些微小的细菌
78. And their billions of descendants...
    以及他们的亿万后代
79. Changed the destiny of our planet.
    改变了地球的命运
80. They transformed its atmosphere.
    它们改变了大气
81. What happened to the carbon that poisoned the atmosphere?
    使大气有毒的碳去了哪里

来自《家园 第一部分 Home Part1》第 78 行