What is certain is that sometime well over a million years ago, some new, comparatively modern, upright beings left Africa and boldly spread out across much of the globe. They possibly did so quite rapidly, increasing their range by as much as twenty-five miles a year on average, all while dealing with mountain ranges, rivers, deserts, and other impediments and adapting to differences in climate and food sources. A particular mystery is how they passed along the west side of the Red Sea, an area of famously punishing aridity now, but even drier in the past. It is a curious irony that the conditions that prompted them to leave Africa would have made it much more difficult to do so. Yet somehow they managed to find their way around every barrier and to thrive in the lands beyond.
可以肯定的是，大约100多万年前的某个时候，一些新的比较现代的直立人离开非洲，勇敢地走向地球上的许多地方。他们迁移的速度可能非常迅速，平均每年增加40公里，一路上跋山涉水，越沙漠，还克服了其他数不清的障碍，他们逐渐适应了不同的气候，不同的食物来源。有一点至今仍是一个谜——他们是怎样穿越红海西部地区的。这一地区现在以气候干燥而著称，而在那时气候更加干燥。很有意思又具有讽刺意味的是，促使他们离开非洲的环境变化使得他们的迁移变得更加困难。尽管如此，他们还是跨越一切障碍，在其他大陆生息繁衍下来。

And that, I'm afraid, is where all agreement ends. What happened next in the history of human development is a matter of long and rancorous debate, as we shall see in the next chapter.
这一点，在我看来，恐怕就是所有一致意见的终点。人类历史凌晨进程接下来的一个阶段是一个长时间争论不休的问题：这一点我们将在下一章里看到。
But it is worth remembering, before we move on, that all of these evolutionary jostlings over five million years, from distant, puzzled australopithecine to fully modern human, produced a creature that is still 98.4 percent genetically indistinguishable from the modern chimpanzee. There is more difference between a zebra and a horse, or between a dolphin and a porpoise, than there is between you and the furry creatures your distant ancestors left behind when they set out to take over the world.
但是，在我们接着往下讲之前，让我们记住，所有这些发生在过去500多万年的一系列的进化，从遥远的、至今仍充满谜团的南方古猿到完全意义上的现代人类，造就了一种动物，其基因的构成仍然有98.4%与现在的黑猩猩一样。一匹斑马和一匹马，或者一只海豚和一只鼠海豚之间的区别，比起你和黑猩猩，这个被你的远古祖先在他们开始接管世界时远远抛到后面的毛茸茸的动物的区别还要大。