Superpowers

Cold is not the obstacle. Ice is.

Nothing biochemical stops working at -15 °C; things merely slow down. The problem is that at -15 °C water is normally a solid, and a cell cannot run on a solid. Planococcus halocryophilus gets around this by living in the brine veins that stay liquid inside frozen permafrost — pockets so salty they refuse to freeze — and by rebuilding its own cell envelope to cope with both the cold and the salt.

It divides down there. Slowly, but it divides.

The record is contested because “deep” quietly means two different things.

Depth below water is a pressure problem and it is basically solved — there is life at the bottom of the Mariana Trench and it is not especially remarkable there. Depth below rock is a different question, and a much better one, because it asks how far life can get from the sun before the arrangement stops working.

The current answer is: several kilometres, in near-total isolation, running on hydrogen split out of water by the radioactive decay of the surrounding rock, dividing perhaps once a century. Which raises the question the record exists to raise — whether that is life persisting, or life living.

It swims at something like a hundred body lengths a second, which is fast enough that the collision with its prey is genuinely a collision.

Bdellovibrio does not eat other bacteria from the outside. It bores through the cell wall, squeezes into the space between the wall and the membrane, seals the hole behind it, and takes up residence inside a living cell that it then digests from within — growing as a single long filament in the space, then dividing into several new predators that break out.

The prey is not killed on entry. It is converted.

A fungus that hunts animals.

Drechslerella grows rings in the soil, three cells to a ring, and waits. A nematode swims through one. Contact triggers the three cells to inflate — inward, into the hole — and the ring closes around the worm in about a tenth of a second, faster than the animal can back out. The fungus then grows into the trapped nematode and digests it.

Soil fungi that hunt are not rare. Soil fungi with a moving part are.

No citation is attached to this record yet, deliberately. The ~0.1 s figure is widely repeated and we have not found the measurement it comes from. Establishing whether it is real is task IZ-028.

Water does not boil at 122 °C if there is enough pressure on it, and at the depth these organisms live, there is.

Methanopyrus kandleri strain 116 was cultured from a hydrothermal vent chimney and grown, under pressure, at a temperature that would sterilise most laboratory equipment. It makes methane for a living. It has no use for oxygen.

The record moves every decade or so, and each move is a story about the apparatus — because the hard part is not finding the organism, it is building something that can keep it alive and observed at a temperature that destroys instruments.

This record has no answer, and saying so is more interesting than picking one.

Every candidate is a different reading of “single cell”. Caulerpa is one continuous cytoplasm shaped like a plant. Valonia is one cell you could hold between two fingers. A xenophyophore is one cell that builds itself a shell out of the seabed. The ostrich egg is a cell only if you are willing to call a yolk one.

What the contest actually shows is that “cell” was a word coined for something at the limit of a seventeenth-century lens, and it does not survive contact with organisms that never agreed to be built that way.

It was not described until 1988. The most numerous photosynthesising organism on the planet, roughly a hundred times more numerous than there are stars in the observable universe, went unnoticed until someone looked at seawater with a flow cytometer and found something too small to have been caught by the nets.

It is a cyanobacterium under a micrometre across. It lives in the sunlit top of the open ocean, where almost nothing else can make a living because there is almost nothing to eat, and it has stripped itself down to suit — one of the smallest genomes of any free-living organism, because in a place that poor, carrying an unused gene is a cost.

A meaningful fraction of the oxygen in the breath you just took was made by something nobody had heard of within living memory.

The interesting part is not that it survives the dose. It is that the dose lands.

Radiation at this level shatters the chromosome into hundreds of pieces. Deinococcus does not prevent that and does not appear to try. It simply reassembles the genome afterwards, over some hours, using overlapping fragments and a spare copy or two, and then carries on.

There is no radioactive habitat that could have selected for this. The leading explanation is that surviving radiation is a side effect of surviving drying out, which breaks DNA in much the same way and happens to organisms constantly. The record is an accident of a more ordinary competence.

Put plainly: nothing alive is older than anything else alive.

Every organism on Earth is the end of an unbroken chain of reproduction reaching back to the same beginning. There are no late arrivals. A human lineage and a cyanobacterial lineage are the same number of years long, and both have been under selection for every one of those years.

What people mean by this record is usually “which lineage looks most like its ancestors”, and that is a claim about rate of change, not about age. It is also much harder to establish, because looking unchanged and being unchanged are not the same thing — and the organisms that look most ancient are often the ones we have looked at least closely.

We keep this record in the hall precisely because the honest answer is that the question is malformed.