Alright I see some people are still a bit confused on what convergent evolution would mean so here's some geeking out by some guy who likes biology
(Note: For the purposes of this post, "Evolution" will be refering to the real life term rather than the game mechanic)
So before we go into Convergence, I wanna go over the opposite - Divergent Evolution. I'm doing this because two species being a case of divergent evolution would automatically disqualify both of them from being a case of convergent evolution with one another.
Divergent Evolution refers to when two species share an ancestor, but at some point in time, the ancestor adapted into different ecosystems or ecological niches and eventually evolved into different species. think stuff like Chimps and Gorillas, or the different subspecies of foxes, or how pelicans, macaws and woodpeckers have different beak shapes to aid with their diet. In Pokémon, the most obvious cases of these would be through some regional variants - At some time in the past some
Meowth adapted either to
Alola's or
Galar's circumstances and became new subspecies (The later of which resulting in a new species altogether with
Perserker)
However, this isn't limited to Regional Variants. The Pokédex confirms quite a few relationship between a few mons. For an example, PLA states that
Pachirisu and
Pikachu are biologically related, meaning they must have an ancestor in common. Similarly, Sword and Shield dex entries also imply that
Toxicroak and
Seismitoad are related. Likewise, we can assume that most canine Pokémon are related, such as say,
Yamper and
Lillipup or
Growlithe,
Fennekin and
Vulpix, meaning that they're a very likely case of Divergent Evolution since they share biological roots.
Archeops is also an acestor to most Bird Pokémon. I'd say this is also where a lot of counterparts, such as
The Simi Triplets or
Milotic and
Gyarados, would fall under.
So next up, how does Convergent Evolution work in the first place, for us to be able to determine what in Pokémon could be considered that? Convergent Evolution, as a term, can refer to varying levels of similarity - As pointed out in a few posts ago, wings are considered a case of convergent evolution when they were developped by bugs, mammals and birds separetely; but there's also way more extreme cases of convergent evolution like Sugar Gliders and Flying Squirrels being bizzarely identical.
So I'd say Wiglett is not the first case of Convergent Evolution in the franchise - See
Amoonguss and
Galarian Stunfisk both evolving to have Pokéball-Looking body parts as means to lure in prey, or
Donphan and
whirlipede both evolving to have bodies that facilitate moving by rolling around like a wheel all the time, all while definitely not sharing any ancestry. These are, in my opinion, definitive cases of convergent evolution (And, if we are to take the wings example from earlier, you could argue that stuff like
Charizard,
Mothim,
Swellow and
Noivern technically are a case of convergence as well)
What I do think Wiglett falls under, though, is the comparison between Sugar Gliders and Flying Squirrels - A convergent evolution that falls to the more extreme end, and in that case I do think its the first one we get (At least that I can think of). Both Diglett and Wiglett are Pokémon that spend most of their times underground, only ever poke their heads out, have poor eyesight and a good sense of smell, so their bodies evolve similar features. Wiglett is also most likely the first time they
intentionally do this rather than making two Pokémon with body functions that happen to overlap. (There is one very weird case though -
the Galarian Birds. Peony and some dex entries vaguely imply that they're not related to the other birds, but the dex still classifies them as the same species they have the same name and the same cry, unlike Wiglett. I can't quite come to a conclusion on them - Part of this feels done to avoid any controversy on straight up making regional variants for legendaries, but part of it also just feels like contextualizing why they still have the names "Freezer, Thunder and Fire" if they're not elemental anymore. Very weird mons overall imo, I kinda get the feeling that TPC themselves were unsure on how they should work.
then again that's just galar lore for you)
So where does the confusion come from and what would this mean for the franchise going forward? I feel like what's making people confused is that
visually it does look like a Regional Variant but it has worldbuilding reasons as to why its not. I can't really blame the general Pokémon audience for not being too invested in lore, though, so I can see why trying to explain why Convergent Evolutions are a different thing than Regionals to someone who isn't that preocupied with lore and worldbuilding could be confusing.
I think the bottom line should mostly be "Does it make sense, even for this fantasy setting, for this change to occur with the given Pokémon?". In this case, where we already know through game descriptions that Diglett has limbs, doesn't live near water and is a Mammal, it wouldn't really make sense for it to become this eel we see right now so they had to make it a different Pokémon. Similarly, in a point I made a few posts ago, Palossand going from being made out of sand to being made out of candy wouldn't really make sense for a regional variant, even if the idea of a sentient candy castle isn't too out there. Another common idea I've seen floating around thefandom before Wiglett's reveal was regional variants for Porygon that turned it into origami - which, once again, while a fun visual concept, wouldn't really work as a variant since Porygon is a digital mon made out of computer code and wouldn't really make sense for it to become paper. The thing that quite a few people miss about Regional Variants is that they're more than just type swaps, they need an explaination (that makes at least
some sense) on how they went from A to B. (
I realise this is a franchise where "A to B" can sometimes mean "Fish to Octopus", but I still think that overall most Pokémon that are connected to one another make enough sense.) With the introduction of Wiglett, you can have your Porigamis and your Candygasts all you want since they wouldn't be too messy lorewise!
As for what it means for the franchise, I think we aren't going to see too many of them. The way I see it, Convergents are an extension of Regional Variants in a way - You could either recontextualise a Pokémon's look and lore to a new region, such as a Wooper that spends too much time on the surface becoming permanently poisonous, or you could reimagine a Pokémon under more out there approaches, picturing how the similarities between the two of them occur. I believe that as we go forward, we're gonna still see more Regional Variants in comparison, but maybe one or two convergent species here and there with wilder concepts like a hummingbird that looks like a pre-existing Bug or a land urchin that sorta resembles Pincurchin or something - stuff that can't logically be a variant, but still be mostly designed like a variant would be.
So, TLDR, idt these mons are gonna be trying to "fix" or replace variants, moreso they're a way for GameFreak to do variant-like designs with more liberty since they can turn the idea into a new mon altogether if needed, not having to be too preocupied on how the other mon would relate to this one.
I am very curious to see how Wiglett relates to Diglett mechanically though - I'd expect it to have some sort of tie back to Diglett but I think they'd also try to differentiate it from Regional Variants, so i'm not too sure how far they'd change Wiglett's mechanics. They would need to find a balance between "not close enough where the changes are functionally a regional variant but not too different where there's nothing that calls back to diglett"