Pokémon Biology: Combined Evolution

Panelists included: Bummer, Arcticblast, bugmaniacbob, Harsha, and macle. Art by Bummer.
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The world of Pokémon is deep. Very deep. So deep that its boundaries cannot be calculated, its contents cannot be determined, and its inhabitants cannot be accurately described with several brief Pokédex entries. We live with them, battle with them, trade with them, and they have shaped our society immensely because of that close relationship. They never remain constant, where new species, traits, and features are discovered continuously as time passes. Many researchers stare into this vast abyss of unprocessed information, trembling before its size. They turn around, walk away, never to conduct research again. And then there are those who gladly tackle this scientific wonderland with interest and delight, eager to explore its secrets. Among these valiant pioneers are the Pokémon Biologists, and tonight, we will invite a few of them to discuss the following theme: Combined evolution.

Most Pokémon evolve independently, either through experience or through
the influence from their trainers. Some don't evolve at all. And then there
are Pokémon who require the aid of another species before they can rise
to new heights, where all species involved may receive different benefits
from the result or not.

The questions the panel will aim to answer are:

  • What happens to the Pokémon during their evolution?
  • Do all species involved gain an equal number of advantages from this process?
  • What possibilities are made available for the new beings?
  • Are there any benefits if they would stay unevolved?

The panel consists of bugmaniacbob, macle, Harsha, and Arcticblast, represented here by Anorith, Sharpedo, Dragonite, and Tynamo respectively.

Mantyke and Remoraid


Remoraid's effect on the evolution of its aquatic friend, Mantyke, is certainly enigmatic. When the little fish is present next to Mantyke, our manta ray friend evolves into Mantine, an even bigger manta ray. Oddly enough, all Mantine seem to have a Remoraid clinging to their underside, cleaning the belly of debris and other fish. Thus, the relationship between Mantyke and Remoraid must contribute something to the evolutionary sequence. What can this be?

Many of us should know that many Pokémon evolve when they are extremely happy. The endorphins that produce happiness in the brain are the same endorphins that we see released from Mantyke's glands when a Remoraid is nearby. It is possible that Remoraid and Mantyke bond in such a way that they make each other very happy, and this happiness is what causes Mantyke to evolve. Scientists are currently researching whether producing this happiness—without a Remoraid—can produce the same result: evolution.

One of the strange things to note about Mantine is that Remoraid never seems to leave Mantine's side. These Remoraid never evolve, and apparently Mantine's presence seems to stunt their growth into Octillery. Of course, an Octillery cannot keep up with a Mantine, so it's possible that the Remoraid itself enjoys sticking with Mantine so much that it prevents its own evolution. These two truly compose one of the more fascinating mysteries of the sea!


A rare sight around the seas of Johto, Mantine biology was not properly explored at all until fairly recently, and as such, even the very existence of its juvenile form, Mantyke, was unknown to most scholars. However, after researchers at Sinnoh were indeed able to identify and confirm its existence (in point of fact, it is quite literally as common as muck in Sinnoh, so you have to wonder how they didn't make the connection sooner), it became a hot research topic for its bizarre method of evolution, which involves the Pokémon Remoraid, a bizarre fish best known for acting as a "cleaner" in underwater communities by biting away pieces of fungus and other potentially infectious pieces from larger organisms, and for undergoing some bizarre form of regressive evolution, reverting from a vertebrate fish to an invertebrate cephalopod form, Octillery, after a sort of metamorphosis.

The life cycle, then, is quite bizarre. It appears that Mantine congregate extensively in coastal areas, such as Undella Bay and the environs of Sunyshore City, until they encounter a Remoraid, at which point they will accompany the fish out to sea, evolving into a Mantine once sufficiently mature, which then migrate to their breeding grounds in Johto—the discrepancy between numbers indicates that very few Mantyke survive the journey. After breeding, the females lay their Eggs in the seabed and abandon them; once the Eggs hatch, the Mantyke must make their way back to the coastal areas, where they will be safe from predators. Even so, large quantities of Mantyke are a big part of the ocean food chain, so at least they're useful for something.


Mantyke and Remoraid have a symbiotic relationship, meaning both of them benefit from living together. Mantyke protects the small Remoraid from being eaten by vicious Pokémon such as Sharpedo and Basculin. Remoraid also feeds off of the scraps of food that Mantyke misses. Mantyke benefits from having a Remoraid around because the Remoraid cleans and protects Mantyke's body from diseases, allowing Mantyke to focus on evolving into Mantine.

There are some downsides for Remoraid when choosing to live with a Mantyke. Once a Remoraid picks a Mantyke to live with, it will always be with that Mantyke for the rest of its life. Also, the Remoraid loses its ability to evolve into Octillery.


The technicalities surrounding Mantyke's evolution pose quite a dilemma for scientists. While the theory Harsha brought up is currently the best explanation the scientific community has to offer, there are a number of things still not known about it. What is known is that the odd prerequisite of a Remoraid appears to be a vestige from prehistoric times, when common fish Pokémon such as Remoraid were stronger and more intimidating. The protection Remoraid may have offered would allow the small Mantyke to concentrate on evolution. After Mantyke had evolved, the Remoraid would spend its life under the fin of the new Mantine, catching scraps from Mantine's meals. While Remoraid doesn't exactly offer this protection today, this behavior is seen in modern Mantyke-Remoraid relationships. Remoraid won't "attach" to Mantyke until it has evolved into Mantine. Regardless of the past, however, Remoraid's role in Mantyke's evolution is still a fascinating topic of study.

Slowpoke and Shellder


Ah. Possibly the single most bizarre evolutionary method to date, Shellder and Slowpoke are a particularly noteworthy example of chimeric evolution—a fusion of two individuals to form an entirely new, evolved form. Advanced horizontal gene transfer, if you like. However, what is special about these two is that they are entirely different species—where Magneton is merely a simple colonial organism, Slowbro and Slowking are both much more than a symbiosis—indeed, it would not be unreasonable to describe it as a chimera, although admittedly the center of neural activity is still up for debate. This has led some to propose that Slowpoke and Shellder should be classified as a single species—that they have adopted the function of being, effectively, very large gametes, and that Cloyster exists purely as a sort of "sperm factory", producing more Shellder for the continued survival of the species.

However, one cannot adopt such a simple explanation too readily, as it ignores a number of crucial pieces of evidence. Fossil evidence makes it clear that Shellder and Slowpoke, whatever they are now, were once separate species, and follow entirely different evolutionary descents. More importantly, Slowpoke and Shellder are rarely, if ever, found in the same areas, meaning that an encounter is often more likely due to chance than design, although it is possible that certain places, such as the Seafoam Islands and Route 205, are like breeding grounds, as the Sargasso Sea is to European eels. A more likely explanation for the above, however, has surfaced recently in comparing the ribosomal RNA sequences of Slowbro "shells" and Shellder, in that the Slowbro "shell" may actually be a new, parallel evolution for Shellder, brought about by enzyme-linked morphological changes initiated by Slowpoke sap, which is entirely parasitic, and is forced to live alongside its host owing to its low defensive stats, manipulating it like some malevolent puppetmaster, and enhancing its psychic capabilities. Certainly it could offer an explanation as to why Slowking appears to possess such significantly developed mental capabilities compared to its prior and parallel forms.


Slowpoke's evolution is quite odd by common evolution standards. After a Shellder attaches itself to Slowpoke, the two begin to live together in a symbiotic relationship. Depending on where Shellder sinks its teeth in, Slowpoke will either evolve into a Slowbro (on the tail) or a Slowking (on the head). In both cases, Shellder suddenly becomes elongated and gray, with spiny protrusions. The two are able to continue living symbiotically because Slowbro and Slowking release sap from their glands, feeding the Shellder they house. Interestingly enough, this sap is the same ingredient that makes Slowpoke Tail a hot commodity.

Scientists have attempted to undo this evolution by removing the Shellder from Slowbro or Slowking. However, after extensive testing, they have concluded that removing this Shellder is impossible, as the Slowbro's tail becomes elongated during the evolution and spirals around inside of Shellder—the inside of Shellder's shell also becomes a spiral maze, making it difficult to remove. In Slowking's case, the Shellder upon its head clamps on so hard that Shellder can only be removed if the will of a partner permits it to. One might notice that Slowking's psychic powers are enhanced by the jewel upon its crown, which actually happens to be a power that Shellder gains through this evolution.


Once the Shellder bites onto a Slowpoke's tail, its poison enters the Slowpoke's body. At first the toxin hurts the Slowpoke, causing him to be weak. After awhile, the Slowpoke begins to resist the toxin and actually gains bulk and better defenses because of the toxin, along with increased pain resistance. This is one of many reasons why Shellder benefits Slowpoke.

After evolution, Slowbro must change the way it obtains food since it can no longer use its tail to fish. Slowbro has been observed burying itself in the sand with its tail out. When an appropriate sea creature passes by, the Slowbro suddenly bounces out of the sand with all of its might and agility (which isn't much) and eats its prey, which could range from unsuspecting Krabby or even other Shellder.


Slowpoke and Shellder's strange evolution is fascinating and unpredictable—will Shellder bite Slowpoke's head or tail? Slowpoke's sap glands are, in fact, only found in these areas, a sign that Slowpoke evolved in this manner to avoid Shellder biting anywhere that would greatly restrict movement. Slowpoke's ability to regrow its tail is a similar adaptation in that it aids evolution. Unlike the glands, its regenerative qualities developed in response to predators such as Basculin that would snatch the tail. Some Slowpoke have gained the ability to regrow their tails in minutes, hence the Regenerator ability designation.

Slowpoke's tail in particular brings a heavy moral debate to the table—quite literally. Slowpoke meat is often toted as tender and quite juicy. Only Kanto and Johto have an ample supply of Slowpoke, however. Scattered farms there provide both premium Slowpoke steak and syrup made from Slowpoke sap. The sale of the tails, however, is highly contested. While they are quite the delicacy, cutting off the tails is excruciatingly painful. The effect of repeated tail removal is even noticeable by eating Slowpoke meat—repeated tail removal causes such stress to the Slowpoke that the meat turns bitter. A series of public protests led the sale of the tails to be banned in several large cities in Johto, while being banned entirely in Kanto. Nevertheless, organizations such as Team Rocket continue to sell the tails through the black market. The International Police have been investigating these sales, but we can only hope the poor Slowpoke can keep their tails.

Beldum, Metang and Metagross


Metagross is one of the most terrifying Pokémon to face in the wild, preying upon Piloswine and Solrock alike. It eats with the mouth on its stomach by smashing its prey into the ground with its massive weight. Even the offspring of such a monster must be pretty scary too, right? Well... not exactly. A simple observation of Beldum or Metang will yield no organ that can be used to consume things. Many scientists believe that Metagross's mouth is formed when two Metang fuse together. If this is the case then, how do Beldum and Metang even exist? It appears that Beldum and Metang are massive energy storage units. At birth, Beldum contain a massive amount of energy, 99% of which is saved to be used toward evolution. Beldum are somewhat unstable, however, and sometimes lose all of this energy. Upon fusing with another Beldum, however, it only needs to store about 25% of this original energy. It also gains tiny holes in its metal that allow it to take in oxygen, water, and particulate matter in the air. Metang begins to grow larger at this stage in preparation for fusion with another Metang. Upon fusion, Metagross keeps these tiny pores but uses them only for oxygen—its newly formed mouth and surprisingly complex digestive system take care of the rest. Metagross's evolution line is truly marvelous!


Metagross's intelligence has been equated to that of a supercomputer, and certainly, if the complexity of its genome offers any indication, this is not difficult to imagine. Metagross's success can largely be linked to its extremely complex life cycle, which involves some form of double-gamete fusion. The following model was developed to explain the phenomenon: Metagross reproduction, poorly understood though it is, produces haploid "spores" that develop into fully functional Beldum. These gametic organisms can live quite happily in the wild, though with limited capabilities, and of the four that are produced in the meiotic reproduction, there are four types—alpha, beta, gamma, and delta. Alpha and beta Beldum fuse to form αβ-Metang, while gamma and delta fuse to form γδ-Metang. This has no bearing on their morphology, but affects the eventual Metagross—an αβ-Metang can only fuse with a γδ-Metang that is not from the same original parent Metagross. Once these Metang fuse, the body is divided up by brain, such that the α-brain coordinates perception and knowledge retention, the β-brain coordinates logic and mathematical computation, the γ-brain coordinates intuition and deduction, and the δ-brain coordinates all other bodily functions. Even after fusion, it is estimated that it takes at least a month before the Metagross is fully mature and can start producing its own offspring.

Interestingly, while Metagross is most commonly associated with Hoenn thanks to the patronage of its former champion, Steven, it is in fact endemic to Unova, where a small native population resides in the Giant Chasm, although research specimens of Beldum have been known to escape in the past, where they have been quickly wiped out. Unfortunately, while Metagross is a formidable organism indeed, its development is so long and time-consuming that it is quite unsuitable for any region other than the one that it developed in, where it has no natural competition bar Piloswine, and Delibird, Solrock, and Lunatone provide an ample prey source—when tested in any region other than the Giant Chasm, the Beldum gametes are wiped out within days. Indeed, although Metagross release thousands of Beldum "spores", less than 1% of them go on to form a Metagross, and when you consider that it takes four Beldum to make a Metagross, this is quite alarmingly wasteful. It is also notable that the Giant Chasm is one of the few places in the world containing wild Ditto, which is intriguing considering that Metagross can only breed in captivity when Ditto are present. Could it be that the Ditto are necessary for Metagross reproduction, and why is this the case? The research, as ever, is ongoing.


Through vigorous research, we have identified that two Beldum form a Metang but the scientific knowledge of how this happens is still unknown. I ponder the question of why is it that there only needs to be two Beldum to form a Metang? If three Beldum fused to create a Metang, would it be stronger than a two Beldum Metang? I researched and experimented endlessly to discover the answers to my question and I believe I have come to a sound explanation. All Beldum posses an electrical charge. This charge is the same for all Beldum. These charges prefer to be with another of the same charge which is why the Beldum form. Once two Beldum form, the charges are satisfied, and no longer have the need to search out more of the same charges, which is why only two Beldum form a Metang.


Beldum and its family are a strange batch of Pokémon in that they fuse together to evolve. Two Beldum are required to electromagnetically bind and form a Metang, while two Metang are required to bind to form a Metagross. As we can see, four Beldum are required to fuse to attain a Metagross. This raises a few questions in my mind, though. For one, can these Pokémon fuse at will, or is there a special force driving the evolution? It may be possible that the stronger a Beldum gets, the more powerful its electromagnetic field becomes, and the more easily it can bind to another Beldum; the same may be true for Metang. One needs to note that while these Pokémon fuse, their internal organs may not. It has been documented that Metagross has four brains, one from each Beldum!

Scientists are currently wondering how Beldum can combine to form a Metagross, considering four Beldum are not near the size of one Metagross. One popular theory suggests that Beldum uses its magnetic powers to attract scrap metal and form parts of the body of Metang, who in turn does the same for Metagross. Another question that some have raised is whether or not it is possible to make a Metagross directly from four Beldum. Scientists are currently subjecting Beldum to intense amounts of electromagnetic waves to see if they can directly bind together to form a Metagross, though this research is supposedly top secret and dangerous.

Karrablast and Shelmet


Common knowledge and Pokédex entries dictate that Shelmet and Karrablast evolve when electrically stimulated in each others' presence, which can be achieved most easily by trading the two Pokémon. To the contrary, recent tests have shown that no common Electric-type attack can stimulate evolution. However, captive populations of Karrablast and Shelmet have managed to achieve evolution, despite a lack of major electrical stimulation.

My colleagues and I have proposed a radical theory on the evolution of the two Pokémon. When fighting, Karrablast and Shelmet release a large amount of pheromones not released otherwise. These chemicals are similar to human adrenaline in that they evoke a strong fight or flight response, the reaction of the Pokémon being to continue their battle. The extreme force of their attacks damages both Pokémon. What is interesting is that these Pokémon store the pheromones released by the other Pokémon in special, highly sensitive glands in their bodies. When a certain level of these pheromones is achieved in the body, even the slight movement of charged ions before a thunderstorm will trigger the release of these pheromones into the rest of the body. The pheromones trigger a massive cellular response that begins the process of evolution. How each Pokémon's evolution is so morphologically similar to the other Pokémon is currently a mystery, as is much more about this process. What is known, however, is that the energy released in a Pokémon trade somehow accelerates this process, although this as well is little understood.


Karrablast—upon first glance—is seemingly one of the wimpiest Pokémon one could ever hope to see. Its minuscule stature of one foot and eight inches and its light weight of just 13 pounds makes sure that its pointy horn is not too intimidating. Shelmet, on the other hand, is quite a reclusive creature. The only part of its body sticking outside of its clunky shell is its face, which interestingly enough, is quite small. While both Pokémon are relatively weak unevolved, a strange thing occurs when the two Pokémon are in the presence of one another. It seems as though Shelmet gives up its characteristic armor in exchange for an agile body. Karrablast, on the other hand, trades its mobility for a suit of armor.

Oddly enough, these Pokémon seem to change their attitudes as well. Karrablast no longer remains the wimpy cockroach it once was; instead, it becomes the well-respected and fierce knight, Escavalier. Shelmet, on the other hand, loses its effeminate lips and becomes shrouded in ninja attire. Its blistering base 145 Speed is simply a testament to Accelgor's newfound masculinity. Could Shelmet's armor be a catalyst for this evolution, both physically and mentally? We may never know, as a full suit of armor is currently irretrievable from Shelmet, at least ethically since this Pokémon cannot survive without it unless evolution occurs.


Shelmet gathers up steel to form its shell to become an Accelgor. Shelmet passes on these techniques to Karrablast so it can adapt and transform the shell and become Escavalier. We introduced Shelmet to other Bug-type Pokémon that gather up items from the environment to create a protective body, to see if other species could make use of the shell in a similar way as Karrablast. One of the first Pokémon we introduced Shelmet to was Burmy. The Burmy was intrigued by Shelmet's shell and began to gather it up, but the steel weighed Burmy down so much that it was unable to move. The other Pokémon was Dwebble. This creature moved quickly into its new home of steel and was released into the wild. When observing the Dwebble, it had a tough time trying to blend into the desert with its new steel home. Eventually, the Dwebble changed homes back to a rock.


Karrablast and Shelmet are a relatively recent entry into the scientific journals, though their peculiar life cycles have been known to Unova's witch doctors for centuries prior. This relationship is all the more bizarre for the fact that, until recently, the two species did not even share the same habitat, an observation that boggled ecologists—Shelmet were found primarily in the watery moors surrounding Icirrus City, while Karrablast were exclusively found in the grasslands far south of there. Currently, thanks to some clumsy students, the two communities have reintegrated and are currently enjoying a happy predator-prey relationship.

The explanation for the bizarre phenomenon of mutual evolution remains a mystery, though that is not to say that hypotheses do not exist. One such theory suggests that the Shelmet and Karrablast once existed in the same ecosystem, and had their own separate evolution pathways, with Shelmet evolving into a slow, powerful "gastropod knight" and Karrablast evolving into an agile, predatory "ninja beetle". However, once geographically separated they lost the ecological need for the evolution, rather similarly to Pokémon such as Kadabra and Machoke, and could no longer evolve without an external energy input that activated the enzymes and proteins necessary for evolution. This does not, however, explain on its own why such a thing should only occur while the two are traded together. Another explanation suggests that Karrablast and Shelmet were originally a single species that underwent allopatric speciation—their isolation caused them to differentiate into two species. This may explain why the two must be combined alongside the energy input, in that possibly some biological controls are retained in one but not the other, and vice versa, but there is no fossil evidence for any common ancestor and analysis of ribosomal RNA sequences suggests that the two are not even closely related, relatively speaking.

Finishing thoughts


And with that, I'm afraid it's time to wrap up the show! Thanks to all of our knowledgeable participants and their fascinating entries about this month's chosen species. I hope you all enjoyed the show, and we'll be back next time with more Pokémon, more answers, and more HARD facts!

See you then!

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