Pokébiology 101: “Evolution” and the enigma of Eevee


(Click here for the introductory post to Pokébiology 101)

You know I had to start my Pokébiology 101 series with the most famously scientifically inaccurate part of Pokémon: evolution.

In the Pokémon world, “evolution” means something different from what you might have learned in your biology classes. …Well, what you should have learned in your biology classes, assuming the religious right failed to push their agenda into your science classroom. Pokémon evolution is when a Pokémon transforms into a different looking creature once some criterion is met. Most often this means reaching a certain level (levels increase as you gain experience, experience comes from participating in battles). Some Pokémon evolve under weirder circumstances like being exposed to a particular item, being traded to another player, reaching a certain level of happiness, and so on.

For example, a Bulbasaur evolves into an Ivysaur at level 16, and an Ivysaur evolves into a Venusaur at level 32.


This is not evolution. This is metamorphosis.

What’s the difference? Why are Pokémon actually metamorphosing, and not evolving? They both imply some sort of change is taking place, which is why the terms are so easily confused. But there’s a major difference in when and where that change happens:

  • Metamorphosis is the change in body structure of an individual that happens conspicuously and abruptly during their lifetime. The most common real world example is a caterpillar turning into a butterfly. This is exactly what happens in the Pokémon world. Well, instead of forming a cocoon, Pokémon flash a bright light and make cheery beeping noises…but I’m going to chalk that up to the games being from the point of view of a ten year old with an overactive imagination. Wee, shiny!
  • Evolution is the change in heritable characteristics of a population over successive generations. A characteristic is heritable if it is genetic, and thus will get passed on from parent to offspring, and from that offspring to its offspring, and so on. The key here is that this change happens over many generations and affects the whole population.

What would be a hypothetical example of actual evolution in the Pokémon world? Let’s say we’ve stumbled upon a population of Venusaurs in some jungle untouched by Pokémon trainers. Most  Venusaurs have pink flowers, but a rare individual has a gold flower because of a mutation. In case you’re wondering, this alternative color scheme exists in-game and is known as a “shiny,” and shiny Pokémon are incredibly rare. Like, “I’ve probably played 1000 cumulative hours of Pokémon games and I only found one shiny Sentret a decade ago” rare.


Now, let’s say that shiny Venusaur is very successful in producing a lot of baby Bulbasaurs for whatever reason. Maybe gold flowers attract more prey, so shiny Venusaur is well fed and can have more babies (directional selection). Maybe other Venusaurs find the rare gold flower extra sexy, so shiny Venusaur has more mates and thus more babies (sexual selection). Maybe it’s all due to random chance and shiny Venusaur just gets lucky (genetic drift). When that generation of Bulbasaurs grows up, the new generation of Venusaurs might look something like this:


If we’re still around to observe this population many generations later, it may look like this:


The shiny trait has now become “fixed” in the population – that is, every individual now has the gold flower. Now the population of Venusaurs looks different than it used to – and that is evolution! If this population is isolated from other Venusaurs and continues to evolve novel traits, one day this population might be so different that it can’t even mate with other Venusaurs anymore. And that, folks, is when you have a new species.

But back to metamorphosis. The common caterpillar example is linear: a caterpillar makes a cocoon and becomes a butterfly. But not all Pokémon have a set fate. I give you the most enigmatic example, Eevee.


Eevee is special in the world of Pokémon because it has the largest number of ways it can evolve depending on your actions. Want a Flareon? Give Eevee a Fire Stone. Espeon? Make Eevee very happy and level up during the morning or day. Leafeon? Level up while near a mossy rock.

It seems like this couldn’t possibly exist within the confines of our natural world, right? How does an Eevee have the ability to metamorphose into such different creatures just from what its exposed to in the environment? How can a Vaporeon, Jolteon, Flareon, Espeon, Umbreon, Glaceon, and Leafeon all have the same genome as their starting Eevee, but such different traits?

Not to erode Eevee’s specialness, but this happens right here on Earth.

This is known as polyphenism: when multiple discrete phenotypes (a set of observable characteristics) can come from the same genetic background because of differences in the environment. The most common example is different castes in bees. You may know that within a hive, one female gets to be the queen bee, and the other females are worker bees. A queen bee is made by feeding a larvae what’s known as “royal jelly,” which contains chemicals that alter the larvae’s development. If that larvae has a twin sister that didn’t get a special meal, sis will grow up to be a worker. They’re genetically identical, but very different thanks to their environment.

The only thing distinguishing bees from Eevees are the number of choices in development.


In which I speculate on what would happen if you gave a bee a Fire Stone or Macho Brace.

It will forever irritate me that the game designers chose the term “evolution” instead of a totally accurate, also cool-sounding alternative word. My best guess is that “Bulbasaur is metamorphosing” took up too many pixels, so “evolving” won out. Sadly, this kind of sloppy terminology can cause a lot of misconceptions about what evolution really means. But hopefully now that you’ve learned some Pokébiology, you’re less confused.



So confused.

Welcome to Pokébiology 101


Hello there! Welcome to the world of Pokémon! My name is Jen! People call me the Pokémon Grad Student!

…Okay, I don’t think anyone has actually called me the Pokémon Grad Student. But I’m a PhD candidate studying evolution and genomics who has been playing Pokémon since its release in 1998. My friend showed me his Red version, and soon after I owned my first video game – Pokémon Blue. I’ve been hooked since then.

As I progressed through my training as a biologist, I started to look at the Pokémon world in a new light. At first, it was irritation. Everything seemed wrong. They confused metamorphosis for evolution. Breeding didn’t make any sense – different Pokémon species could interbreed, but the offspring were always the same species as mom. Gender ratios didn’t reflect biological mechanisms, but rather a game designer’s attempt to keep certain Pokémon rare. Why, it was if they were trying to design a fun game with no regard to biological accuracy


darwin heart piplup by claudetc

But as I learned more biology, I started to realize nature isn’t as simple as it seems. There are all sorts of strange biological phenomena that result in counter-intuitive mechanisms, traits, and organisms. Nature is really, really weird. So I started viewing the Pokémon world as a puzzle. If I were Professor Oak, what experiments would I be doing? Are there any natural processes in the real world that could explain Pokémon biology?

Bulbasaur Anatomical Study by JoshuaDunlop

Some of you must be thinking, “Jen, it’s just a game. It’s not supposed to make sense. Chill.” I know, I know. I don’t expect all games to be 100% scientifically accurate at the expense of fun. But I like daydreaming about how the biology of Pokémon could “work.” It’s as if I’ve discovered a whole planet of alien life to study, and what biologist wouldn’t want that?

But more importantly, I see the Pokémon world as a great way to teach people about actual biology. And I’m hardly the first person to think this – the creator of Pokémon originally conceived of the game as a way to share his childhood hobby of collecting insects with the children of a modern, urbanized Japan. But I’ll be discussing what I know best: evolution and genomics. How do Pokémon species differ from species here on Earth? What does genomic imprinting have to do with breeding? Can an organism like Eevee actually exist? I’ll be exploring these topics in future PokéBiology 101 posts.

Now, there are some things in the Pokémon Universe that are above my pay grade. I’m not even going to attempt to explain how a tiny mouse generates thunderstorms or how some Pokémon have psychic abilities. I have no clue how a Pokéball can transform Pokémon into pure energy and back again (maybe a bored Physics grad student can hazard a guess). And there’s certainly no explanation for how Onix, a ground/rock type, suddenly becomes vulnerable to electric attacks because a sprinkler system came on (yes, I am still bitter about that episode).


 I have no idea how this works.

For all of those things, I’m willing to suspend disbelief. But when it comes to the biology of the Pokémon world, I’ve found it’s not necessary to invoke “magic!” as an explanation. Because oddly enough, that bizarre biology is already happening here on earth.

Welcome to PokéBiology 101!

Next in series: “Evolution” and the enigma of Eevee

Come see me at Nerd Nite Seattle!

I am living the dream: I’ve been invited to give a talk of extreme geekiness this Monday:

Pokébiology 101
There may not be a Pikachu Genome Project, but the unusual biology of the Pokémon Universe can teach us about biology in the real world. How do Pokémon species differ from species here on Earth? What does genomic imprinting have to do with breeding? Can an organism like Eevee actually exist? You won’t need to be a Pokémon Master or geneticist to catch the concepts, so come, have fun, and grab a beer – it’s super effective.

Nerd Nite Seattle
Monday, January 21st
7:30 Talks (Doors open at 6:30)
$5 Cover
LUCID Jazz Lounge

If you drop by, make sure to say hello!

Geeky filler

Sorry for the dearth of posts lately. Between PAX and moving, I pretty much haven’t been on the internet at all. I went four days without checking emails, which I think in a new record for me. Anyway, I’m still unpacking and doing other apartment related stuff (woooo, Ikea run!), but I wanted at least some kind of filler. So, uh, here’s me cosplaying at PAX as the main character from Pokemon Black & White:
…Not quite a 12 year old Japanese girl, but close enough.

Probably the best compliment I got was that two random people asked me where I bought my hat…but I painted it! Without tape or drawing circles! Freehand! I’m just that awesome.

I am a geek


1. I just bought this:I love Saturday Morning Breakfast Cereal, dinosaurs, and surrealism. How could I not resist?

2. Next weekend I’m going to PAX Prime, the ginormous gamer festival that’s the brain child of the guys who make the webcomic Penny Arcade. When I say ginormous, I mean ginormous – over 60,000 people have attended in the past. I’m a huge video game geek and haven’t been to any sort of geeky convention since ACen in high school, so I’m looking forward to it. The tournaments haven’t been announced yet, but I’m hoping at least something I’m good at will pop up. Mario Kart plz? Or if we’re going esoteric, Pokemon Puzzle League?

And unlike the poor shmucks who are flying in and have to deal with hotel, transportation, and food confusion, I can just hop on my same ol’ bus to downtown! Huzzah!

Upon further reflection, I just realized I’ve been reading Penny Arcade for over 10 years now. I feel old.

3. I became overly excited when I found out that there’s an unofficial Pokemon League taking place during PAX. Yeeessssss! Time to tweak my party in Pokemon White, charge my DS, and prepare to get my ass kicked. Seriously, I’m great at in-game battles, but I’ve never played competitively. People get pretty hard core about Pokemon. IV breeding and EV training lolwut?

If you’re going and can hunt me down in the crowd of 60,000, feel free to challenge me to a battle (or say hello, if you’re not a Pokemon geek like I am). I’m sure I’ll be tweeting the whole time, making con-stalking even easier.

4. Speaking of Pokemon… I’m currently constructing my cosplay as Hilda from Pokemon White:Don’t judge.

I have to give a shout out to my mom, who’s dealing with my geekery. I made her hunt through my old bedroom for my Burger King Pokeballs (which apparently suffocated small children) and mail them to me to complete the costume. Now I’m just trying to hunt down some cheap boots and a hat that I can alter with pink paint. May have to give up on a pink purse. EDIT: Boots and purse acquired at thrift store! Now just for the hat, shoelaces, and wrist band thingies. I AM GOING TO BE SO COOL.

5. And if that’s not enough, I just bought my ticket to Geek Girl Con in October.

I am in geek heaven.

Homeopathy in Pokemon?!

Super Potions: Heals 50 HP, costs 700 PokeDollars
Fresh Water: Heals 50 HP, costs 200 PokeDollars

Why…Super Potions are just fresh water that have been marked up because of the fancy label! I’m sure if you read the fine print there’s something about “parts per million” or “Not approved by the PokeFood and Drug Administration.”

Where are all the skeptics in the Pokemon universe to out this scam? Maybe they’re too busy fighting off swarms of Woobats.
…Don’t worry, I’m about the beat the Elite Four, so Pokemon talk will die down soon.

(Via reddit)

Dear Everyone Who’s Buying Pokemon Black/White Today

I hate you.


A certain blogger who is working in the lab and doing exams constantly and can’t play until Friday and wonders how she’s supposed to be the very best like no one ever was if she starts a week late, goddamnit