One of the big challenges now is to figure out just how many viruses there really are in the human genome. So far the estimate is 8.3% of our genome is virus, but it actually could be a lot higher.

Medicine allows people to live who would otherwise die, so antibiotics will let people survive infections that they might be otherwise very vulnerable to and even little things might make a big difference, so I wear eyeglasses because my eyes aren't particularly strong, before there were eyeglasses someone at my age would probably not be good for much.

When you get sick with the flu you get infected with flu viruses and they make lots of new flu viruses, but those new viruses are not exact copies of the old ones. They have mutations in them. A lot of those mutations are harmful.

Over millions of years the viruses in our genome mutate more and more so the look less and less and less recognizable as viruses and so if there was a virus that infected our pre mammal ancestors like 250 million years ago, which it probably did, we can't see it because it just looks totally random.

We really depend on viruses for our complete survival.

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

One of the big challenges now is to figure out just how many viruses there really are in the human genome. So far the estimate is 8.3% of our genome is virus, but it actually could be a lot higher.