Waters et al. have recently reported the discovery of an ancient, hot-vent-dwelling nanobe called Nanoarchaeum equitans9; genome size, proportion of junk DNA, and diameter are all in the ßehemoth ballpark. Even better, it's a parasite/symbiont (it lives on a much larger Archeon called Ignicoccus). However, its minimalist genome (about 500 kilobases, half the size of ßehemoth's) lacks the recipes for certain vital enzymes, which it must therefore get from its host. It could never be a free-liver. ßehemoth, with its larger genome, is more self-sufficient—but how it crams all those extra genes into a capsule only 60% the size remains a mystery.

The fishheads and the corpses got into a bit of a debate about the odds of ßehemoth hitching a ride in the flesh of dispersing larval fish. I was always worried about that myself, even back when I was writing Starfish—if true, there'd be no reason why ßehemoth would not have, in fact, taken over the world billions of years ago. Invertebrate larvae do seem to cross vast distances in the deep sea; fortunately they generally go into a sort of arrested development en route1, making them unlikely carriers of ßehemoth (which needs an actively-metabolizing host to withstand long-term thermo-osmotic stress). It also appears that even highly-dispersing larval fish species maintain fairly distinct geographic ranges, judging by the lack of genetic flow between populations around adjacent islands10,11. Worst comes to worst, local topographic and chemical conditions can constrain the distribution of various deep-water species12,13.

So I dodged the bullet. This was not prescience on my part, and it may yet come back and bite me in the ass: at least one adult fish may have swum through deep water from Patagonia all the way up to Greenland14.

Seppuku

Artificial microbes are almost mainstream these days: J. Craig Venter (the Human Genome guy) has completed an entirely artificial genome even as I type15, hoping that such organisms will be able to cure the world's environmental ills. Peter Schulz and his team have already tweaked E. coli to synthesize a novel amino acid not found in nature16, hoping it will be able to outcompete the baseline strain. Entirely synthetic organisms, built from interchangeable genetic modules, are just around the corner17. I wish all these guys better luck than Jakob Holtzbrink's gel-jocks had when they tweaked ßehemoth.