for the first time to infect human beings.

或至少是传染源时以此称呼它
These are diseases--

这些疾病包括
in our own day we can think of Ebola or Lyme's disease,

现在所知的埃博拉病毒莱姆关节炎
SARS, or of course, most importantly, HIV/AIDS.

非典当然还有最重要的艾滋病
Often the press--which seems,

媒体经常
I would argue, to suffer chronically from historical amnesia--

由于长期的历史健忘症
it often treats the appearance of new infections

而把新的传染病看做是
as something unprecedented, unnatural, that never happened before.

一种全新的非自然的疾病
But the reality is that Charles Darwin was correct.

但事实上查尔斯达尔文是正确的
We live in the midst of a constantly evolving microbial world

我们正生活在一个微生物不断进化的世界
in which the microbes have an inherent advantage

微生物因其频繁的变异
because of the frequency of their mutations,

而占有遗传优势