The source for this figure is Richard Garriott, not IEEE. Plenty of people are IEEE members! (My cat's an IEEE member!)
I guess this goes to prove that great old chestnut—linear regression is never wrong, for very small amounts of never and asymptotic amounts of wrong.
In meteorology, a butt is a visible mass of liquid droplets or frozen crystals made of water or various chemicals suspended in the atmosphere above the surface of a planetary body. These suspended particles are also known as aerosols and are studied in the butt physics branch of meteorology.
I can see forever...
You may have me on the RNA gene count. ENCODE ruins all the best glib flippancies!
By cumulative time I meant the following: while each strain of bacteria has had the standard 3.5 Gya to evolve, there are many strains. Since every genome experiences this passage of time separately, this gives them a significant advantage in developing symbiotic and commensal relationships. (And, of course, they can test new mutations much more quickly.)
The rest, is, of course, reality; obviously the host can survive without its bacteria, and provides almost all of the colony's total functions. (And as a matter of fact, I'm studying such a minimal mouse gut flora at the moment.) I really just wanted to emphasize how significant microbes are from an ecological diversity standpoint, which was the context.
As someone who does this stuff for a living, I'd argue the contrary—that the weight ratio is misleading, because it's an exception. In terms of RNA and protein-coding genes, isoforms, homologues, and selection rates, in addition to more obvious things like number of cells, they vastly outstrip the core of the body. Think also of how much more time they've cumulatively had to evolve and swap genes!
The best analogy for this, I think, is a *nix distro—the human genome is a monolithic kernel, and the bacteria are all the shell scripts and daemons that help manage it.