Evolution

File:Evolution VIII.png
**Evolution** (Japanese: **進化** *evolution*) is a process in which a Pokémon changes into a different species of Pokémon.

With respect to real-world phenomena, Pokémon evolution is more similar to metamorphosis than evolution. Evolution is mostly independent from the aging process, instead being triggered by external factors, such as gaining experience in battle or being exposed to certain items.

Evolution is not a merely visual change, as Pokémon of a higher evolutionary stage have different (and usually increased) stats, can learn different moves, and sometimes change types (although normally at least one of the pre-evolved form's types remains the same). Pokémon may also change Ability upon evolution.

Professor Elm and Professor Rowan are the leading experts in Pokémon evolution. According to Rowan's research, over 90% of all Pokémon are connected to at least one other through evolution. Currently, the actual percentage is 75% of all known Pokémon. Rowan's research focuses on whether evolution is a form of maturity in Pokémon, and looking at the implications of the process on Legendary Pokémon (which could not evolve in Generation IV, when Rowan debuted).

## Evolutionary families

 File:Piplup family anime.png
An evolution family is a group of Pokémon who are all related by evolution. The species at the lowest evolutionary stage in an evolutionary family can ultimately evolve into any member of the evolutionary family.

### Evolutionary stages

Pokémon evolutionary families have anywhere between one and three stages. In a one-stage family, there is only a single Pokémon that cannot evolve. In a two-stage family, any member of the family can evolve at most once, from the unevolved form into one of the evolved forms. In a three-stage family, at least one of the evolved forms can evolve once again.

In the Pokémon Trading Card Game, Pokémon are divided into four different categories: Baby Pokémon, Basic Pokémon, Stage 1 Pokémon, and Stage 2 Pokémon. Pre-evolved forms introduced in a later generation than their evolved form are classified as Baby Pokémon so that the evolution stages of their evolved forms are not disrupted.

#### One-evolution families

*See also: Category:Pokémon that are part of a two-stage evolutionary line*
These are evolutionary families in which a Pokémon can only ever evolve once. These are the most common type of evolutionary families. An example of this type of evolution family is below.

#### Two-evolution families

*See also: Category:Pokémon that are part of a three-stage evolutionary line*
These are evolutionary families in which a Pokémon can evolve twice. All starter Pokémon, except Pikachu (in

## Evolution

) and Eevee, have this type of evolutionary family. An example of this type of evolution family is below.

#### Pokémon that do not evolve

Main article: List of Pokémon that are not part of an evolutionary line
These are evolutionary families with a single member, which cannot evolve. Many of the Pokémon that have no evolutionary relatives are Legendary or Mythical Pokémon, although there are some Legendary and Mythical Pokémon that can evolve, and some Pokémon that aren't Legendary or Mythical that cannot evolve.

#### Branched evolution families

Main article: List of Pokémon with branched evolutions
Several one- and two-evolution families are also branched evolution families. A branched evolution family has a member that can evolve into one of several different Pokémon. Eevee is the most extreme example, having eight different possible evolved forms. An example of this type of evolution family is below.

## Methods of evolution

Main article: Methods of evolution
In the core series games, Pokémon normally only evolve after one of three events:

* Gaining a level (the most common trigger)
* Being exposed to an item (such as an Evolution stone)
* Being traded

Before Generation VIII, the above were the only triggers to evolve Pokémon. However, Generation VIII introduced several new triggers, each used either by a single Pokémon species or by two.

In addition to the trigger, many Pokémon have one or more additional requirements for them to be able to evolve. These include, but are not limited to:

* Having high friendship
* Holding a specific item
* The time of day
* Knowing a certain move or a move of a certain type
* The location the player is in, or the current weather in that location
* Having a certain Pokémon in the party, or a certain type of Pokémon
* Being upside-down
* Being traded for a specific Pokémon

Some evolutions are dependent on the Pokémon's gender. For example, only female Combee can evolve into Vespiquen—male Combee cannot evolve at all. Similarly, all Snorunt can evolve into Glalie, but only female Snorunt can evolve into Froslass. On the other hand, male Burmy can only evolve into Mothim, while female Burmy can only evolve into Wormadam.

For some evolutions into Pokémon with multiple forms, the form of the evolved Pokémon depends on how it evolved. For example, Wormadam's cloak depends on the cloak Burmy had when it evolved. Similarly, the form of Toxtricity which Toxel evolves into depends on its Nature.

## In the core series

When a Pokémon evolves, it becomes a new species of Pokémon. This new species has a different Pokédex number and base stats, and may be a different type, learn different moves, and have a different Ability. The Pokémon's personal properties, however, such as Nature and Shininess, remain.

Holding an Everstone prevents a Pokémon from evolving by level up or trade. Additionally, the player can prevent a Pokémon from evolving upon leveling up by pressing the B button when it would evolve. In

## Evolution

, if the player does not have the National Pokédex, if a Pokémon in the Kanto Pokédex meets its evolution conditions but its evolved form is not in the Kanto Pokédex (for example, Chansey's evolution into Blissey), it will attempt to evolve but fail.

When a Pokémon evolves, it immediately attempts to learn all moves that the evolved form can learn at its current level. Additionally, starting in Generation VII, some Pokémon have Evolution moves, which are moves that Pokémon will always attempt to learn when evolving into that species, regardless of level.

### Abilities

Normally, a Pokémon will retain its Ability slot upon evolution - if it had its species second Ability before evolving, it will still have its species second Ability after evolving (e.g. a Poochyena with Quick Feet will still have Quick Feet after evolving into Mightyena, but Poochyena with Run Away will instead have Intimidate after evolving.).

However, some Pokémon originally from the Generation III games can change Ability slot upon evolution. When Abilities were introduced in Generation III, some Pokémon only had one possible Ability but were given a second Ability in Generation IV. If a Pokémon whose species gained an Ability after Generation III is transferred to a Generation IV or V game, it will initially retain its original Ability; upon evolving, however, its Ability slot will be recalculated and its Ability may change. When a Pokémon is transferred to Generation VI or Generation VII, however, it will be locked into the appropriate slot for its current Ability.

### Animations

In Pokémon Sun, Moon, Ultra Sun, and Ultra Moon, evolution into an Form has a different theme and a different colored background during evolution. In Pokémon Scarlet and Violet, if there is enough space around the player when a Pokémon evolves, the area that the player is in will be used as the background and the camera can be moved, but if there is not enough space, the game will cut to an abstract colored background with a fixed camera for the evolution like in previous games.

Uniquely, if Tandemaus levels up to level 25 or higher in a battle it was not sent out in, it will evolve into Maushold immediately after the battle ends with no animation.

## In spin-off games

### Pokémon Mystery Dungeon series

Main article: Evolution (Mystery Dungeon)

## In relation to the real world

Evolution in Pokémon is closer to the real-life phenomenon of metamorphosis rather than actual evolution, as real-life evolution happens to populations over a long period of time, not to individuals. In the Pokémon Adventures manga, it is mentioned that Pokémon Evolution is an entirely separate phenomenon from the normal process of evolution, and is a mysterious ability exclusive to Pokémon that is still not fully understood. In Pokémon Super Mystery Dungeon, it is described in the health class at the school in Serene Village as when a Pokémon's body rapidly grows larger with many other changes bringing a Pokémon closer to being an adult, being described akin to puberty.

Real life evolution still appears to have happened in the Pokémon universe and is mentioned or referenced in multiple media. Different Pokémon lines are related to each other evolutionarily, but not necessarily all of them as some are man-made, spiritual or alien in their nature. There's also Sinnoh Folk Story 3 which claims there was a time there was no difference between Pokémon and humans. Many Pokémon can interbreed based on their egg group pointing towards their close relation. Pocket Monsters Encyclopedia describes how Pokémon adapt to different environments and uses Cinnabar Island and its unique ecosphere as an example which is thought to have strongly influenced its native Pokémon, like Growlithe, and now is famous as a home to many Fire-type Pokémon. Starting with the Generation VII games, each new region features new forms of previously known Pokémon called regional forms which look different, most of the time have different type and sometimes evolve into brand-new Pokémon species, and starting with the Generation IX games, "regional fakes" or "convergent forms", Pokémon that appear to be regional forms but have no relation to one another, have appeared in the Pokémon franchise, based on the real-life phenomenon of convergent evolution.

Other mentions:

* Drowzee is said to have descended from the legendary beast, Baku, and is also thought to share common ancestry with Munna and Musharna.
* Omastar's heavy shell is thought to be the reason this ancient Pokémon died out. It's apparently a distant ancestor of Octillery.
* Gastrodon is relative of Shellder and Cloyster, this ocean dweller sometimes comes onto land.
* Seismitoad is a related species to Croagunk and Toxicroak.
* Skorupi shares a common ancestor with Sizzlipede.
* Aerodactyl was a progenitor of birds that roamed the skies in the dinosaur era. A widely accepted theory is that it went extinct due to a large meteor impact.
* Archen is believed to be a progenitor of bird Pokémon, although some of the latest research suggests that may not be the case.
* Tirtouga is reputed to be the ancestor of most turtle Pokémon, it lived in warm seas approximately a hundred million years ago.
* Anorith and Armaldo are said to be a type of Pokémon predecessor who swam in primordial sea and have been determined that it is the ancestor of some bug Pokémon.
* Lickitung's ravenous appetite and a lazy nature must have shaped its evolution, which allowed its tongue to move as if it were an arm and hunt with it.
* In Zubat the process of evolution made its eyes regress and disappear, as instead of sight it uses ultrasonic cries for moving around in murky caves.
* Some Doduo have a newly discovered mutation that causes them to prefer running to flying, hence it is feared their wings will become unable to be used to fly.
* Relicanth is a Pokémon species that existed for a hundred million years seemingly without ever changing its form.
* Kabuto have been purportedly discovered in the wild, albeit extremely rarely. If true, this Pokémon has not changed at all for 300 million years.
* Kabutops was apparently evolving from being a water-dweller to living on land to pursue its prey, as evident from the beginnings of change in its gills and legs. However, the mutation did not occur fast enough, causing it to go extinct as its preferred prey left the water.
* Bagon's belief that it will be able to fly one day is apparently the influence of information carried in its genes. Some theories suggest that its behavior affected its evolution.

### Generation AN-I to AN-V

There are several mentions of real-life evolution within Generation AN-I to AN-V as well. In these games, Pokémon Evolution is always capitalized, while the real-life phenomenon is not. Anything in the following list should not be considered canon, as the Generation AN series has no relation to the developers of the main series.

* Gothitelle and Reuniclus are both thought to be closely related to each other and to humans, explaining why some humans have psychic powers. Specifically, the latter is thought to have speciated when an embryo's mental faculties developed so quickly that it was able to survive with no host body.
* Both of Dracozolt's root species appear to be, respectively, a predecessor to and successor to Archen.
* Talonflame and Blaziken's flame sacs are significantly different mechanically, indicating convergent Evolution.

## Trivia

* Of all non-Legendary and non-Mythical Pokémon, 90.87% are part of an evolutionary line.
	+ Counting Legendary and Mythical Pokémon, 84.19% of all Pokémon are part of an evolutionary line.
* Out of all Pokémon that evolve by leveling up, Larvesta evolves later than any other unevolved Pokémon, starting at level 59.
* Of all the Pokémon that evolve by leveling up, Hydreigon evolves from its pre-evolution later than any other Pokémon, starting at level 64.
* Generation III introduced the most non-Legendary and non-Mythical Pokémon that do not evolve, with 18.
	+ Generations IV and VI are tied for the fewest, with just five each.
* All species of Pokémon in Pokémon Legends: Arceus can be caught without using evolution, since the Daybreak update. Only the  Form of Ninetales cannot be caught and must be evolved from the gift Alolan Vulpix.

## See also

* List of Pokémon by evolution family
* List of cross-generational evolution families
* Evolution item
* Mystery Dungeon evolutionary items