They could help scientists understand not just when higher life forms evolved, but why.

它们将不仅仅帮助科学家理解高等生物何时出现，还有为何出现的问题。

youdao

Suppose the evolution of higher life forms takes another couple billion years, as it did here.

再假设更高级形式的生命要再花几十亿年才能进化，就如地球上所经历的那样。

youdao

All the other life forms seem to get the picture but we humans just cannot get our minds around it and instead demand and then legislate the existence of some higher purpose or mission.

其他物种似乎都自得其乐，只有我们人类总是无法释然，一定要得到、继而严格确认某种更高级的目标或使命的存在。

youdao

And we also know that several have happened in the past leading to the extinction of all higher life forms at the time.

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