After that, all the bacteria inside Paul Bunyan and his ox Babe left their bodies, and circulated in the warm water lying on the bedrock, deep underground. They ate methane and hydrogen sulfide, and withstood the weight of billions of tons of rock, as if they were living on some neutron planet. Their chromosomes began to break, mutation after mutation, and at the reproduction rate of ten generations per day, it didn’t take long for good old survival of the fittest to make its natural selections. And billions of years passed. And before long there was an entire submartian evolutionary history, moving up through the cracks in the regolith and the spaces between sand grains, right up into the cold desert sunshine. All kinds of creatures, the whole spread— but everything was tiny. That’s all there was room for underground, see, and by the time they hit the surface certain patterns were set. And there wasn’t much to encourage growth up there anyway. So a whole chasmoendolithic biosphere developed, in which everything was small. Their whales were the size of first-day tadpoles, their sequoias were like antler lichen, and so on down the line. It was as if the two-magnitude ratio, which always has things on Mars a hundred times bigger than their counterparts on Earth, had finally gone the other way, and piled it on.

And so their evolution produced the little red people. They’re like us— or they look kind of like us when we see them. But that’s because we only ever see them out of the corner of our eyes. If you get a clear look at one you will see that it looks like a very tiny standing salamander, dark red, although the skin apparently does have some chameleon abilities, and they are usually the same color as the rocks they are standing among. If you see one really clearly you’ll notice that its skin resembles plate lichen mixed with sand grains, and its eyes are rubies. It’s fascinating, but don’t get too excited because the truth is you’re not ever going to see one of them that clearly. It’s just too hard. When they hold still we flat can’t see them. We would never see them at all, except that some of them when they get in a mood are so confident that they can freeze and disappear that they will jump around when they’re in your peripheral vision, just to blow your mind. So you see that, but then they stop moving when you turn your eye to look, and you never can spot them again.