The vermin only teaze and pinch Their foes superior by an inch.
So, naturalists observe, a flea Has smaller fleas that on him
prey; And these have smaller still to bite ‘em, And so proceed
ad infinitum. What’s the most common living thing on Earth? A
smart guess would be to start with bacteria, which make up over
half of all biomass on Earth (you did watch that episode of my
YouTube show, right?). And since the oceans cover considerably
more than half the planet, a marine bacterium would also make
sense. Until very recently, almost everyone with an opinion on
these things would agree. See that bacterium in the electron
microscope image above? It’s called Pelagibacter ubique, an
ocean-dwelling microbe whose family of relatives make up a
stunning one-third of aquatic life forms (by sheer numbers). Why
so numerous? One popular theory was that because they are immune
to infection by bacterial viruses, they could grow unchecked.
Thanks to some creative science, that theory now appears dead
wrong (here’s the paper