The Pokémon World and our own world are similar in that the natural processes that govern life produce some strange creatures. Perhaps one of the most odd (and unsettling) is Exeggutor, the dual Grass Psychic-type that wanders around with its three grinning coconut heads resembling some unholy hybrid between a palm tree and several stoners. Yet our anthropomorphic palm tree friend is quite the interesting specimen when put under the lens of real-world biology.
A Free-Thinker of Many Heads
The most obvious abnormality of Exeggutor at first glance are its three heads, each with their own distinct and unsettling facial expression. According to the PokéDex entry in Pokémon Gold Version, “Its three heads think independently. However, they are friendly and never appear to squabble.”
This leads to quite the impressive nervous system, especially for a plant. But quips about plants not having any neurons aside, it is not unfounded in nature for animals to have multiple “brains” per say. For instance, octopi have nine brains, the main brain being located in its head with eight auxiliary brains in each of its eight tentacles. When an octopus desires to operate one of its arms, the main brain sends a single message to the nerves located in its arms, and then the arm “brain” proceeds to carry out the order all on its own. Even when severed, an octopus arm will still respond and react to stimuli the same way it would if it were attached to the complete organism and main brain1.
However, unlike Exeggutor, the auxiliary brains of an octopus do not have their own consciousness. A severed octopi arm does not a new octopus make.
A particularly fascinating condition is that of polycephaly. A polycephalic organism is born with two or more heads, either as a supernumerary body part or as completely separate beings sharing a body, as the case is with Exeggutor. Usually the result of faulty twinning, polycephaly never results in more than three heads (tricephalic), with two being the norm (dicephalic). Unfortunately, in both humans and animals, dicephalic organisms rarely survive, as the two heads will often fight with each other for control over the body, often becoming disoriented, which makes for difficulty in fleeing predators. Polycephalic snakes have been known to even attack and consume their other head. Thankfully, Exeggutor appears to be a peaceful organism and its heads are very cooperative, as “they never appear to squabble”.
As deleterious as this condition may be in our world, the trait seems to be of advantage in the Pokémon World. In the Crystal Version PokéDex, “Living in a good environment makes it grow lots of heads.” Apparently the selection pressures of the Exeggutor’s ecosystem make it so that having multiple heads is an advantage, running completely counter to our world which usually follows a general rule of the more appendages an organism has to manage the more energy required to maintain them all. In the game of evolution it’s all about the costs and rewards, having an extra head or two is just too taxing and hardly reaps any benefits.
While selection of polycephalic individuals may seem paradoxical at first, there is good reason for the Coconut Pokémon to expend energy growing its extra heads, and the answer lies with the endgame of survival, arguably the purpose of life – reproduction.
Dropping Heads: Clonal Fragmentation
Counter to what is portrayed in the videogames, Exeggutor does not need another Exeggutor (or any Pokémon of its egg group) to reproduce. In its natural environment, when not forcibly bred by overanxious trainers eager to create an IV master race, Exeggutor can reproduce asexually simply by parting with one of its heads.
More specifically, Exeggutor appears to reproduce through clonal fragmentation, a form of asexual reproduction most common in flatworms, sponges, annelids, sea stars, as well as mold, lichens, types of cyanobacteria, and many plants.
The process of fragmentation involves a piece of the organism splitting off to regenerate into a complete organism that is also able to reproduce. For example, tapeworms live in the digestive tracks of mammals, usually dogs and sometimes humans (either intentionally or, depending on the type of person, on purpose). As you can imagine finding a mate in the middle of a dog’s small intestine can prove troublesome, but all a tapeworm has to do is release an end segment of its own body down the track, and with some time Rover will have an infestation of new tapeworms, grown from the end bits of the original pioneer that first ventured into his bowels.
As is common in binary fission, this often results in the regenerated fragment being genetically identical to that parent, making all Exeggutors clones of each other, the regenerated offspring of past Exeggutors whose heads grew too large to support. However, this process, as is the case with most forms of asexual reproduction, does have one major drawback, in that since all organisms are effectively clones of each other, there is no variation, and as any good biologist (or PokéBiologist) knows, genetic variation is the driving force of natural selection and therefore evolution. But this shouldn’t be a problem for Exeggutor, they seem to be plentiful enough, and pending an Exeggutor superbug, they will continue to endure for many generations to come.
Of course, there is the unique caveat that with Exeggutor, a single fallen head does not a new Exeggutor make, rather the individual Exeggcute have to swarm together, usually in groups of six in order to eventually “evolve” into an Exeggcute. Communicating telepathically, these eggs seem to form somewhat of a superorganism…but that is a topic for another day.