It used to be thought that only a certain kind of virus could get into our genome and it's called a retrovirus and that's a virus that might be HIV for example.

Viruses don't just make us sick. They can actually sometimes end up in our genomes.

Researchers keep identifying new species, but they have no idea about the life cycle of a given species or its other hosts. They cut open an animal and find a new species. Where did it come from? What effect does it have on its host? What is its next host? They don't know and they don't have time to find out, because there are too many other species waiting to be discovered and described.

I wouldn't be a very good hunter without these glasses. I'm not a very good hunter with these glasses, but I'd be even worse without them, so that would put a crimp in how many kids I could have, so all of these medical advances have at least in some parts of the world blunted natural selection.

The reason that viruses are so hard to fight, the reason for example we need a flu virus every year is that they evolve very fast.

At long last, we may be returning to the original two-sided sense of the word virus, which originally signified either a life-giving substance or a deadly venom. Viruses are indeed exquisitely deadly, but they have provided the world with some of its most important innovations. Creation and destruction join together once more.

We really depend on viruses for our complete survival.