If you're that way inclined you're not going to take solace from one of the lead authors' airy What could possibly go wrong?: [Cosmos quote] To begin with, he says, if such a plague were possible, it would probably already have been produced by offshore drilling, which has long been stirring up similar sediments on a much larger scale. But the reality is that bacteria in the deep seabed aren’t something we need to worry about. “Pathogens are common in harbors,” D’Hondt says, noting that these are places easily contaminated by human waste. “But they’re not common in the deep ocean or the sediment. It’s just the wrong environment for them.” Like bats or sooty mangabeys are the wrong environment for human pathogens . . . until they're not.
We need to take on board Tony Kavanagh's comment "extraordinary claims require extraordinary levels of proof" about the outlandish and rapidly discredited claim that some bacteria use arsenate instead of phosphate in the backbone of their DNA. Anyway, let's look at the science which claims that
- The sea floor is covered with a sediment of organic matter of which whale-fall is only the most dramatically lumpy.
- Oxygen gets carried deeper in the sludge as more debris accumulates on top
- Their deepest sediment cores are 100 million years old.
- That there are microbes of that vintage which have been marking time on a minuscule energy budget repairing DNA damage and probably reproducing on a very slow cycle
- That these microbes represent taxa which The Blob is familiar: Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, Actinobacteria, Bacteroidetes
- That 99% of them have been brought to vibrant life when given a warm bath and a good feed.
They have been able to separate out single microbial cells grow them up in the lab and sequence their 16S RNA, which allows these antient bacteria to be slotted into the Tree of Life by comparing their 16S sequences to known bacteria. That's where the diversity list in the penultimate bullet [above] comes from. These bacteria have been living in tiny pores in these clay sediments, only a tiny fraction of the revivified bacteria come from phylogenetic groups in which spore formation is characteristic. Jaysus, what a life! It's like living out the endless days in a dark coffin deep in the earth, if these poor microbes ever got an itch, they haven't been able to turn around to scratch it. Nevertheless, and to bring this essay full circle: "There are more [ways of making a living] in Heaven and [beneath the] Earth, Bobatio, than are dreamt of in your philosophy".