If Mew existed before Mewtwo, why does Mewtwo come before Mew in the pokedex numbers?

Gwpn11

VvSensei

With no confirmed sighting before Mewtwo was created, Pokémon researchers thought Mew may have been just a myth. Mewtwo's creation may have confirmed Mew's existence in a way.

Hey_PIKMIN

Mew only existed because they had leftover code in Red and Blue so it would've been weird to put Mewtwo behind it

TheJeffers

I am surprised to hear anyone ask this, but I guess it makes sense. The franchise is decades old at this point, and even foundational knowledge of the series is unknown to fans who started with later games.

As others have alluded to in the thread, despite being the first Pokémon trademarked (points for anyone who can name the first one designed) Mew was not actually in the game code when it went gold, only mentioned in the lore and in reference to Mewtwo's creation.

One of the developers changed the code after the game had already been tested and approved to enable Mew to be downloaded. Quite risky at a time when there was no internet connectivity to allow patching if it broke the game. (Not that Red and Green weren't broken anyway.)

In universe, Mew is said to have only been a rumour, only confirmed to exist after Mewtwo had already been created using its DNA.

UnovanZorua

I don't think Mew was seen as a myth or rumour- people thought it was extinct and didn't exist at all anymore, with not even enough fossils to fully revive it. The Pokédex is a list of all Pokémon confirmed to exist right now, meaning Mew couldn't be a part of it. Mewtwo, however, was confirmed to exist before a live Mew was found again, meaning it got into the Pokédex before Mew could.

NoahLaprasForum

mewtwo was released before mew