This is a [[SisterTrope counterpart]] to the FisherKingdom, except it is the outsiders that willingly impose the transformations upon themselves, rather than the environment.

For example, humans are attempting to colonize an alien planet, but unfortunately, [[DeathWorld it's quite unpleasant to live on]]: to actually ''survive'' on the planet, you'd either have to wear space suits and build sealed cities to shield you from its atmosphere and hazards, or [[GoingNative go native]]. But if you have the technology, you can do ''exactly'' the latter: Change and adapt your species to enable you to survive on the planet and become one of its native inhabitants.

There are two ways of doing this: The short-term version affects specific individual persons only, while the long-term solution affects the entire colony, becoming a part of the planet's evolutionary chain, possibly becoming a dominant species with the original humans remembered only as ancient {{Precursors}}. Over time, the transformed may also become mentally alien as well as they adapt to the planet's nature, or the mental changes are immediate and directly connected to the process of transformation.

Expect lots of HollywoodEvolution and LegoGenetics.

If the transformed species ever meets its original version, expect to find AnAesop about WhatMeasureIsANonHuman (if from the humans' point of view) and/or HumansAreBastards (if from the natives' point of view).

Often results in HumanSubspecies, HeavyWorlder is a specific subtrope adapted to differing gravities.

Not to be confused with EmpathicShapeshifter.



[[folder:Anime & Manga]]

* A ''Anime/{{Doraemon}}'' Tool allows an individual to adapt to any environmental condition, no matter how extreme (high temperature, high gravity, non-breathable atmosphere, etc). The drawback is that it must be reapplied to each individual every 24-hours. [[spoiler:Giant and Tsuneo was nearly crushed by the oceanic pressure when they wandered away from the underwater summer camp without Doraemon's permission.]]



* {{Marvel|Comics}}'s 1970's ''{{Guardians of the Galaxy}}'' series. Lead by Vance Astro, the secondary members of the team were former humans bio-engineered to survive the harsh conditions of the other planets of the Solar System.



* This is a major part of ''Film/{{Avatar}}'''s plot, though humans don't change their bodies, instead remotely controlling eponymous avatars.
* In ''Film/{{Pandorum}}'' the colonists were injected with mutagens designed to help them adapt to Tanis. But because the ''Elysium'' was cut off the first ones to wake up evolved into albino cannibals over the centuries.



* Creator/CliffordSimak:
** In the ''City'' series of novels, the only way to survive on Jupiter is to become a Jupiterian. When such a technology is discovered, people find out that Jupiterians are absolutely superior to humans in every single way: they are immortal, superintelligent, telepathic, etc. Thus everybody just moves to Jupiter, and humanity as a species ceases to be.
** ''Literature/WayStation'' briefly mentions a race of aliens who colonized numerous planets, regardless of the conditions, by physically and mentally changing themselves every time to perfectly fit those conditions. The main character wonders whether can they be counted as the same race.
* In one SergeyLukyanenko short story the protagonist, who possesses the ability to automatically adapt to anything pefrectly, is hired to deal with a dangerous predator on a distant planet. Gradually adapting to the DeathWorld in question he understands that the dangerous predator in question could not possibly hunt humans for fun as described, as he actually became exactly like him, physically and mentally. When the two finally meet, they start playing as cats do... which gives the colonists a perfect opportunity to kill both with a single rocket, since both aren't technically human and they don't have to pay him this way. [[spoiler:He survives, and briefly mentions before leaving that ''they'' are the ones who are not human.]]
* In the ''Literature/HyperionCantos'', we eventually learn that this is how the Ousters came to be - pioneers of interstellar travel, they had to radically alter their biology to survive. When rest of the humanity finally caught up with [[FasterThanLightTravel Hawking drives]] and means for terraforming, Ousters [[WhatMeasureIsANonhuman became persecuted]].
* The stories in Creator/JamesBlish's collection ''The Seedling Stars'' are all about adapting humans for new planets. For example, in "Surface Tension," humans colonize a mostly water-covered planet by creating a race of humanoids out of their own genes hand-crafted to best suit this planet, and leaving all their knowledge, up to and including how to build spaceships, in form of tablets to be read when they develop enough to manage to do so. The driving point of the story is that being made to perfectly suit the world in question includes being ''microscopic''.
* In Jack Chalker's ''Literature/DowntimingTheNightSide'', it's said that most of the humans who moved to other planets had to radically alter their bodies to survive; most don't even look human now, though they still think of themselves as such.
* In ''All Tomorrows'', humans intentionally modified themselves to live on Mars. Then they went on to colonize other worlds, but kept their new form - large chests, bigger heards, slender hands and so on. Then the AbusivePrecursors stepped in and modified the humans on each planet into something that can perfectly live on the world they colonized, but is rarely even humanoid, just to have fun.
* The Sci-fi novel ''I, Weapon'' deals with a universe that is essentially the aftermath of this with hundreds of variant human species who have adpated to the various planets of the universe, albeit in some cases with extensive genetic manipulation.
* ''Literature/TheVorkosiganSaga'' gives us the "Quaddies"; humans genetically engineered for life in microgravity, the most drastic and visible alteration being a pair of extra arms where a baseline human's legs would be. They were created as an outright SlaveRace, and ended up having to flee Earth en masse when ArtificialGravity made them redundant, and by the time of their first chronological appearance they've built themselves a thriving civilisation.


[[folder:Live Action TV]]
* In ''Series/{{Andromeda}}'' there are several subspecies of human genetically engineered for different planets, including heavyworlders like Dylan's mother, Castalians with gills, Inari adapted to volcanic planets, and Nietzscheans who were designed as generalists that were even more adaptable than baseline humans.

[[folder:Tabletop Games]]

* In ''TabletopGame/TranshumanSpace'', Mars is terraformed, but not to the extent that normal humans can cope with the conditions. Most of the population still live in pressure-domes, but a sizable minority have been "bio-modded" to fit the environment. In addition a large minority of the Rust China population are [[ArtificialHuman bioroids]] genetically engineered for Mars.
* Similarly ''TabletopGame/EclipsePhase'' has "Rusters" adapted to semi-terraformed Mars, as well as "Hazers" that can take the extreme cold of Titan slightly better and "Dvergar" {{Heavy Worlder}}s for a few exoplanets with high gravity.
* In ''TabletopGame/{{Warhammer 40000}}'' the Tyranids start out an invasion by dropping 'nids with different mutations on a planet and multiplying the ones that survive best. They also absorb genetic material from organisms they consume.


[[folder:Video Games]]

* In ''VideoGame/{{Killzone}}'', the [[ANaziByAnyOtherName Hellghast]] are the result of colonists adapting to a DeathWorld. They aren't happy about it.
* The Zerg of ''StarCraft'' acquire new mutations similarly to the Tyranids. Half the "evolution missions" in ''VideoGame/StarcraftIIHeartOfTheSwarm'' involve strains that evolved from exposure to hostile environments (up to and including [[NuclearNasty nuclear missiles]]) and the other half involve killing and consuming creatures with useful genes.
* ''VideoGame/{{Evolva}}'': According to the backstory, the Genohunters are used to exploration tasks because of this trope. They somewhat show it in the actual game: the DNA you acquire from the native wildlife will improve your physical condition, thus allowing you to perform better across the levels.
* ''VideoGame/SwordOfTheStars'' has several technologies that modify your colonists to reduce the "hazard ratings" of planets, making them easier to colonize.
* In ''VideoGame/{{Stellaris}}'' the Gene Tailoring tech allows you to modify the traits of species in your empire, including changing their environmental preferences on certain planets. Though it may sometimes be easier to uplift species that evolved on planets with that environment.


[[folder:Web Comics]]

* The 'Amphibians' of ''WebComic/GeneCatlow'' colonize other planets using this method - but on Earth, they screwed up somehow. Seeing as Earth is mainly ocean, they figured that an amphibian form would work best there - while failing to notice intelligent life evolving on dry land at the same time.
* It's also referenced in ''Webcomic/{{Freefall}}''. Florence, an uplifted wolf, is a 'proof of concept' for a process designed to uplift and educate a species from a fertile-but-biologically-hostile world called Pfouts - rather than altering humans to be alien, it's a case of altering aliens to be human.


[[folder: Web Original]]
* ''OrionsArm'': Most [[HumanSubspecies "Tweaks"]] are meant for extreme environments ranging from underwater to space.