At night, humans do rather poorly: we can't see objects well, our color vision is entirely lost,
晚上,人類的活動力相對差些。我們看不太清物體,我們的顏色辨別也完全消失了,
and we don't have the smelling or hearing acuity of other animals.
而且我們還沒有其他動物那么敏銳的嗅覺和聽覺。
So it actually does make sense to have us stay put during the dangerous period when "nocturnal," or night-waking, animals are on the prowl.
所以在那些夜間活動的動物們出沒覓食的危險時刻,我們保持原地不動,確實是很有道理的。
And one sure way to make sure we don't stumble around and get lost or eaten is to have us immobilized for seven or eight hours,
一個確保我們不會跌跌撞撞,不會迷路或者被吃掉的穩妥方式就是,每天休息七到八個小時,
rising again only when the light is back and our survival chances are better.
天亮了我們再起床活動,這樣我們的生存機會會更好地得到保障。
It's not the only reason we sleep; but in terms of evolution, it may have been one of the first reasons --
這還不是我們睡覺的唯一原因;但就人類進化而言,它可能是其中一個首要原因——
perhaps even the most important one.
甚至還可能是最重要的一個原因。
譯文來自可可英語