What would life look like if it had evolved from viruses instead of bacteria? Maybe it’s what you see in the mirror, jokes Bill Nye – before setting the record straight. Most evolutionary biologists agree that bacteria-like organisms are the ancestors of humans. About two billion years ago, eukaryotes forked off from bacteria, eventually giving shape to humans, animals, plants and fungi. It’s anyone’s guess what kind of organism you’d get from the evolution of viruses but, says Nye, it’s very reasonable that there is a common chemical ancestor for both viruses and bacteria, and if someone wanted to roll up their sleeves, it would be possible to prove it. Bill Nye’s most recent book is Unstoppable: Harnessing Science to Change the World.

Bill Nye’s most recent book is Unstoppable: Harnessing Science to Change the World.

Viewer: Hey Bill. I'm just curious, what would life look like if it had evolved from viruses instead of bacteria?

Bill Nye: Maybe life did evolve from viruses and we just don't know it. However, it sure looks like bacteria went off on their own. And talking some more about me, in my book Undeniable, which I like to think of as a primer on evolution, I speculated that viruses should have their own domain of life, the vera, which in the Latin would be a second declension noun. In Latin apparently they did not have a plural of virus, they never needed one, they never used it in the way we use it today. So I don't know if life evolved from viruses, but in my own experience I am thoroughly charmed by the science fiction story Andromeda Strain where the compartmentalization of the chemicals needed for life was done with crystals rather than with membranes. And it's science fiction everybody, but bacteria are different from viruses in that bacteria have these separate structures whereas viruses seem to be a single molecule, what you might think of as a single molecule. And so viruses are more akin to proteins than they are to bacteria, but proteins are created by bacteria so it is very reasonable that there is some ancestor to viruses and bacteria so that they have in common a common chemical ancestor. Proving that seems to me it should be possible.

When I was growing up people celebrated and questioned and thought hard about the Miller Urey experiment or Urey Miller experiment done by these two scientists who tried to create the conditions of the primordial earth in a big glass flask. And apparently the one thing they didn't all the way figure out was sulfur, which now people generally believe would have come into the earth's atmosphere from volcanoes.

I was in school at Cornell University I walked into the Space Sciences Building when Carl Sagan was very active and teaching classes and stuff and they had the Urey Miller experiment running. It was a big glass flask with these electrodes sparking because it was presumed or is presumed that in the ancient atmosphere there was lightning and this electricity could cause chemical changes that would have been very, very fast. And so the idea is that you would look for or try to create molecules that through their natural existence created copies of themselves. And so that was the goal.

It turns out that creating amino acids, these are biological molecules that have a carbon with a double bond and an oxygen on the side, amino acids aren't apparently that hard to create. And we find them in asteroids and we find them all over the earth and scientist or chemists have been able to create amino acids that have the same pattern but don't exist in nature or we haven't found them in living systems, instead they're very similar but we don't find them in nature. So all this makes me think that it is reasonable that someone could create something akin to these primordial atmosphere primordial conditions on earth experiments that would make molecules that replicated themselves. And we would find that maybe there is a common ancestor to both viruses and bacteria. Whoa. Would that molecule be dangerous? Would it be like the super virus or the super bacterium? Intuitively I don't think so because we're all here. Whatever happened happened and it didn't kill us. So maybe you'll be the guy that figures out the Urey Miller and the next step, the next step of Urey Miller, the next step of self-replicating molecules with primordial components. It is a very compelling idea. Keep us posted.