Experiments on living systems
Surprising discoveries about living things that are basic research, not technology. Each topic lists Known properties: only what the cited papers found. Uses that researchers themselves have proposed are kept separately on Potential uses. Organisms that regrow body parts are on Regeneration.
Organisms that revive from dormancy
- Ancient bacterial spores (disputed revivals)3 studies · Researchers have reported reviving bacterial spores sealed in amber and salt for millions of years. These claims are disputed, because modern contamination is hard to rule out.
- Cryptobiosis: animals and plants that revive6 studies · Some organisms can shut their metabolism down almost completely and come back to life later, sometimes after tens of thousands of years.
- Extreme survivors (tardigrades and rotifers)2 studies · Some tiny animals can dry out or freeze and come back to life after space exposure or thousands of years.
Life at deep-sea vents, without sunlight
- Hydrothermal vent life and chemosynthesis3 studies · At deep-sea hot springs, whole animal communities live without sunlight, fed by bacteria that get energy from chemicals.
- Hyperthermophiles: life above boiling3 studies · Microbes from deep-sea vents that grow at temperatures above 100 °C.
- Pompeii worm2 studies · A worm that lives on the walls of black smoker chimneys, among the most heat-tolerant animals known.
- Scaly-foot snail (iron-plated armor)2 studies · A deep-sea vent snail whose foot is covered with scales made of iron sulfide minerals.
- Thermus aquaticus and Taq polymerase4 studies · A hot-spring bacterium whose heat-stable DNA-copying enzyme made modern PCR testing practical.
Other remarkable organisms
- Deinococcus radiodurans3 studies · A bacterium that survives radiation doses that shatter its genome, then puts its DNA back together.
- Hydra (no aging)2 studies · A tiny freshwater polyp whose risk of dying does not rise with age.
- Lenski long-term E. coli evolution experiment4 studies · Twelve populations of E. coli have been evolving in flasks since 1988, letting scientists watch evolution happen.
- Naked mole-rat3 studies · A long-lived rodent that resists cancer, survives without oxygen for minutes and does not seem to age.
- Single-cell learning and decisions (ciliates)2 studies · Single-celled ciliates like Paramecium and Stentor show surprisingly complex behaviour.
- Turritopsis "immortal" jellyfish2 studies · A jellyfish that can turn back into a juvenile polyp after reaching adulthood.
Behaviour, signalling and memory experiments
- Bacterial chemotaxis4 studies · Bacteria steer toward food by swimming in runs and randomly tumbling, a simple strategy for navigation.
- Bacterial quorum sensing1 study · Bacteria release signal molecules and change behaviour once enough of them are present, a kind of chemical vote.
- Bird magnetic sense (cryptochrome)2 studies · Migrating birds sense Earth's magnetic field, likely through a light-sensitive protein in their eyes.
- Electric eel5 studies · Electric eels generate shocks of hundreds of volts with stacks of specialised cells.
- Engineered living building materials2 studies · Building materials that contain living microbes, which can harden the material by making minerals, repair cracks, or even grow new generations of the material.
- Fungal electrical spiking1 study · Mushrooms and their root-like networks produce trains of electrical spikes.
- Octopus arm autonomy2 studies · Most of an octopus's neurons are in its arms, which can move with surprising independence.
- Plant electrical signalling2 studies · Plants have no nerves, but a wounded leaf sends fast electrical and calcium signals that warn the rest of the plant.
- Plant memory (Mimosa pudica)1 study · The sensitive plant folds its leaves when touched, and can learn to stop reacting to harmless disturbance.
- Plant nanobionics (sensor plants)2 studies · Plant nanobionics adds nanoparticles such as carbon nanotubes to living plants to give them new abilities, like boosting photosynthesis or signalling when they detect a chemical.
- Slime mold problem solving (Physarum)3 studies · A brainless single-celled slime mold that finds short paths, builds efficient networks and seems to anticipate repeating events.
- Swarm decision-making (bees and ants)3 studies · Bee swarms and ant colonies make group decisions with no leader, by simple signals between individuals.
- Synthetic gene circuits2 studies · In 2000, two landmark papers showed that genes could be wired together like electronic parts, giving bacteria a memory switch and a ticking clock. They are often seen as the start of synthetic biology.
- Xenobots (reconfigurable organisms)2 studies · Tiny living machines assembled from frog cells into shapes designed by computer simulation.