When Pokémon Go took the world by storm earlier this month, Satoshi Tajiri’s Pocket Monsters left their traditional ecosystems — middle school cafeterias, Las Vegas cage matches — and ran wild through American cities. In some cases, the Pokémon seemed similar enough to normal animals, albeit imbued with magical powers and improbable physical attributes. But Pokémon clearly belong to their own phylum, existing apart from the natural order and obeying different sorts of natural laws. Dr. Matan Shelomi, a fellow at the prestigious Max Planck Institute, has spent a lot of time and effort working to understand those laws.

In July of 2012, Shelomi, then a Ph.D. candidate at UC Davis, and three colleagues published a paper entitled “A Phylogeny and Evolutionary History of the Pokémon” in the Annals of Improbable Research, a scientific journal run by the same organization that hands out the Ig Nobel Prizes each year.

Shelomi is a legit scientist. But he’s also a lifelong Pokémon fan, and he found a unique way to bring his chosen field together with the tiny Japanese battle monsters. Shelomi studies entomology and was curious about the emergence of Pokémon’s distinguishing traits. He and his colleagues used a sophisticated genetic simulation program and created the Pokémon Phylogeny Tree, a comprehensive evolutionary sequence of the greater Pokémon family, which you can view in full here

Inverse caught up with Shelomi recently to talk about what inspired him to apply his scientific training to the world of Pokémon.

Just a portion of the Phylogeny Tree created by Dr. Shelomi and his colleagues.

What was the first Pokémon game you ever played?

My first game was Pokémon Stadium for the N64. But I loved the show and my junior high classmates played the card games at recess.

Have you played Pokémon Go yet? (Our interview took place before the July 13 launch in Germany)

I have yes. I got it as soon as it came to the U.S. so I found a copy I could use in Europe.

Your paper is very serious in nature, like a real scientific study in spite of the subject. What prompted you to do that? I guess you’ve been a fan of Pokémon for a long time?

There’s such a huge overlap between Pokémon, zoology, biology, and the actual research. I think the kind of people who eventually become biologists would be the same kinds of people who enjoy playing Pokémon, and I happened to be just at that right age when that was hitting the U.S. So definitely my generation, especially in the biology department, is full of Pokémon fans. I think from the start I kind of had the idea of doing the phylogeny of it. Biologists all love Pokémon, but we’re all annoyed by the fact that they refer to what is obviously a metamorphosis as evolution. They completely use the term incorrectly. [We want to ask] what is actual evolution, what that would look like in the Pokémon world?

Could you maybe go into detail what you mean when you say there’s a difference between metamorphosis and evolution? Can you explain a little bit about how Pokémon gets it wrong?

Within Pokémon, an individual evolves into another stage. So you have the little caterpillar Pokémon evolves into a cocoon Pokmon evolves into a butterfly Pokmon. That’s not evolving, that’s metamorphosis. Where you have the little cat evolves into a bigger cat, that’s not evolution, that’s puberty or growth. Evolution doesn’t happen within an individual, it happens to a population, changes in their genetics. So evolution is not the right word, but it stuck. I know there are quite a few biology professors, since everyone knows Pokémon, they actually do use it as an example of what is not evolution.

The paper said that you went through 16 million iterations of the evolution, how long did that take to run those simulations?

I think that took about 4 days of computer time, we ran it over a weekend. The software we ran it on is legitimate phylogenetic [a system of showing inferred genetic relationships] software.

So you took a real scientific approach to this.

My [Ph.D.] advisor does insect systematics — the evolution of real insects — so I thought I can finally in my free time get this data set on Pokémon, and somehow convert it into a format that the software can understand, then run and then see if I can actually get [it] published.

And so you just let it run the 16 million times just to make sure it did it right, and you got this tree?

No tweaking, what you see is what came out of the program. There are errors in there — Golbat is within the bug types, which doesn’t look right to me. That’s what we call long branch attraction, it’s just a problem in the calculation, but you know those do happen when you make the analysis, any phylogenetic tree made with these software in studying real animals, it has to be interpreted, it’s just what the computer spits out. You can interpret it and point out ok maybe the computer was wrong here, so no I don’t think Golbat is a bug type but that’s just an error in the calculation.

How is doing an evolutionary tree in a Pokémon world different from the real world?

Well, we didn’t want to do it by morphology — the way they look — there’d be too many biases in that and it’s not like it would be particularly useful because they’re all designed to look very differently. So we wanted to do something resembling molecular biology, but they don’t have DNA obviously, but something similar, something that they all have that would be slightly different. I figured there are the preprogrammed attack sets and the types and the body types could work. Anything that could be categorized. Something that has been given an explicit category and isn’t subjective. So not like how many legs they have but can they do this attack or not.

You said in the paper that the traits of the Pokémon aren’t passed through DNA. Did you have any theories as to how Pokémon pass their traits?

Seeing their reproduction doesn’t follow the biological species concept. Meaning, a species cannot reproduce outside of its own species, for Pokémon this is not the case, so I have no idea how their reproduction works, genetically or physically. A whale mating with a teeny tiny cat, that raises questions.

Sitoshi Tajiri developed the game because of his love for insects. As an entomologist, was that part of your inspiration? An ode to the original?

The story I know is that he was an amateur entomologist and he liked going and collecting insects. Which is apparently much more popular in Japan than it is in Western countries, but he imagined ants crawling along the link cable from one Gameboy to another and he thought: “Wouldn’t it be fun if you had a game if you could go and catch insects and go and trade them with your friends?” Which is what is actually done in Japan — some people do catch insects and trade them. It’s quite a lucrative market in some regions. We’re seeing that with Pokémon Go, it’s coming full circle: while people are going and looking for Pokémon, they’re finding actual animals and insects. They’re taking pictures of those and posting them online and asking people, “What is that?” So actually, I think Nintendo’s been trying to do this for years and now they’ve finally succeeded in coming full circle and taking the love of going out and looking at insects and turning it into a game and now going back to a love of going out and collecting.

Anything you can think of that would be interesting other than what you’ve already told me?

I don’t think anyone has ever noticed or pointed out but of the four authors, one of them is not a real person.

Ok so I reached out to Andrew and Ivana, but not Yukinari Okita? I’m assuming that’s a character from Pokemon?

Exactly, his English name would be Professor Oak. Myself, Ivana, and Andrew I guess you can say we’re the only people who’ve co-authored a paper with professor Oak.

Photos via Annals of Improbable Research, Giphy