Dragon Ball is the host to a plethora of characters, and not all of them are like typical humans. While Saiyans are more human-esque in form, they are a far cry from humanity. On the other hand, creatures like Majin Buu are born out of evil and destructive tendencies. Similarly, Akira Toriyama has created some fascinating species for the franchise.
An interview between Masayuki Kato, a science teacher and writer specializing in Biology, and Yudai Okuyama, a researcher specializing in evolutionary biology, led to an engrossing discussion on evolution in Dragon Ball. The center of discussion for this article would be the Namekians.
Did Akira Toriyama Create Namekians to Gain Energy Through Photosynthesis?
Namekians are green-skinned humanoids who also have slug-like characteristics like antennae. In the Dragon Ball anime and manga, it has been explicitly stated that the Namekians do not need food to survive like humans; their only sustenance is water. The bodies of Namekians have enzymes that can convert water to nutrients. The digestive system of Namekians can also handle milk, as shown in Dragon Ball Xenoverse 2.
This led to a discussion among the two Dragon Ball enthusiasts as they began to wonder how the Namekians could rely solely on water. Mr. Okuyama suggested,
In terms of biology, I’d propose that they get their energy via photosynthesis, just like plants. They are green, after all.
Mr. Kato then explains that Planet Namek does have three suns and no nighttime, making photosynthesis the ideal method of generating energy. Due to the environment they live in, they can get plenty of sunlight throughout the day as well as enough air. Thus, water is the only external factor they require to survive.
Are Namekians an Evolved Form of Sea Slug-like Creatures in Dragon Ball?
There are animals whose bodies contain chloroplasts that use photosynthesis to generate energy. Mr. Okuyama pointed out corals as examples. A species of sea slug called Plakobranchus ocellatus also looks close to a Namekian. Just like how humans evolved from apes, Namekians might have evolved from a kind of sea slug.
Kato jokingly added:
I can imagine if they had an encyclopedia of evolution on Planet Namek, there’d be an entry with a picture of one of these guys, saying, “This is you—500 million years ago!”
The biology experts further point out a tree in Planet Namek called Ajisa, that looks like a round bulb of leaves that stands right at the top of its thin trunk. On Earth, similar trees are found in tropical rainforests. The reason they grow to resemble this specific shape is that in dense rainforests, areas other than the top canopy are unsuitable for photosynthesis.
The hypothesis of Mr. Okuyama is that Planet Namek used to be an abundant paradise before a radical climate shift occurred. Thus, Ajisa might have evolved to thrive in densely populated forests. However, the land became more barren but the tree’s evolution did not change so drastically.
You can read Dragon Ball on Viz Media and watch the anime on Crunchyroll.