It's impossible to overstate just how aggressively life evolves to suit new environments. It just keeps pumping out slight variations on the theme until something succeeds, no matter how many wither and die in the process (like pop music executives, but less soulless). An amazing example is Halomonas titanicae, designed for only one thing: eating Titanics. Which proves that either life adapts to new environments or an Intelligent Designer has one bastard of a sense of foresight.
And on the fifth day, the Lord took a nanosecond to tune one of the countless millions of bacterial species to eat metal. He planted it on the seafloor, and lo, spake "Wait there a couple of millenniums and I'll kill over a thousand people to feed you. Mysterious ways."
This bacteria eats Titanics. Titanics are not something the seafloor has many of. Titanii are not naturally occurring. But we did once drop 50,000 tons of iron on the seafloor, and given the choice between Leonardo DiCaprio's corpse and a rusting hulk, Nature learned to eat metal. The multiply prefixed gammaproteobacteria was recovered from the wreck, and despite every convention for things recovered from the deep darkness, the site of a mass catastrophic death and the discovery of a new species that can eat metal, it didn't immediately consume the science probe and learn of our existence. Instead, it kept doing what it adapted to do: eating the goddamn Titanic.
Scaremongers say it's only a matter of time before we destroy the ecosystem, and they give us way too much credit. We could vaporize the surface of the Earth to a depth of 2 miles and nuke what's left, and some species would say "Finally! Our time to shine!" Radiation-eating species live 3 miles straight down in a world without the sun, which means they live in an endless energy-deprived hell, but at least they don't have to deal with idiots painting themselves bright orange.
A team of researchers found these autochthonous organisms at the bottom of a South African gold mine. They were lucky because life is priceless, which means you can't sell it, which means the mining company had zero interest in discovering a new kind of ecosystem. The scientists were kindly allowed some analysis time while the miners were preparing to excavate a new tunnel, and just as you'd expect from teams delving the bowels of the Earth, they found something where the sun don't shine. Literally. They discovered a life form utterly cut off from sunlight, aka "the source of everything living you've ever seen." This entirely separate ecosystem replaced photosynthesis with the scientific spirit of the '50s: the life-giving power of uranium, thorium and potassium, which is always fun for wet and living things!
The bacteria harvest the energy released by these exciting elements, eating radioactively transmuted rocks, drinking the hydrogen peroxide runoff and making a total mockery of our human Iron Stomach competitions. Millions of years ago, they decided that the sun, until then the fusion-powered font of all life on Earth, was for pansies. Uranium Bleach Rock might sound like a band that "plays" guitars by smashing them off the mosh pit's heads, but that's what these things eat. Like most things living in deep dankness below normal human street level, they're not very quick and don't breed fast. While many bacteria can replicate every hour, these can manage it about once every 300 years. Many of the bacteria down there predate human religion.
The lesson of Chernobyl is that the most dangerous substance in the world is human stupidity. If everyone who whined about nuclear technology actually understood it, the world's average IQ would increase by 50 points. When idiots drink and drive and kill thousands, we don't ban cars. But when idiots run emergency shutdown tests with an untrained night crew without telling the designer of the reactor or nuclear authority scientists, then deliberately drive the reactor into the nuclear equivalent of "balanced on tiptoes on a stool perched on a stepladder on a table ... made of plutonium," suddenly all nuclear power is evil. Those responsible were so bad at planning that their driving tests all end with proctologists, and they're not allowed to undress themselves without three handlers and a fire extinguisher.
"Critical is bad? Boy, is my face red! Or it will be when the massive radiation burns set in!"
The sheer resilience of life was proven when we sent a robot to observe the shattered heart of the Chernobyl reactor number four, ground zero of the worst nuclear accident in history -- and found something growing. The robot found black slime growing inside the actual casing of the exploded reactor, which was a nice touch, but perhaps Mother Nature was being a little theatrical. Cryptococcus neoformans is darkened not by a heavy-handed metaphor but by melanin pigment so intense it not only protects them from gamma radiation, but they actually grow faster when exposed to these lethal levels of radiation.
Some scientists theorize that they've adapted to use nuclear radiation as a power source instead of the sun. They're not just the Hulk of microorganisms, but much more successful than the Hulk of humans -- they actually found a place they can live in peace without people bothering them. (For a guy who whined about being left alone, Bruce Banner spent an awful lot of time alternating between major metropolises and shit-kicker towns where hassling strangers is the local sport.)
Marvel, Universal TV
Sorry, but this picture is way funnier than any of the comics.
The melanin has an altered chemical structure and magnetic properties to deal with the increased radioactivity. These cells have visibly evolved in response to one of the most dramatic events of the last few decades. They're incontrovertible proof of adaptation by life, in the last place on Earth you'd expect to find something living. Although it is the first place you'd expect a radioactive mutant.