Worldbuilding Alien Species Based on Real-World Species
- Casey Hudson
- Sep 4, 2023
- 4 min read
Updated: 3 hours ago
If you’ve been watching my videos for a while you may remember a video about writing alien species. Updated and with more visuals, I’m pulling it from the archives for another go. Enjoy this walkthrough on how I alter a baseline species to create a fictional one.
One way I like to approach worldbuilding alien species is by using real world species as a baseline. To make them believable, I have to decide what biology to keep, and what to change.
I’ll use my tadaribrae species as an example.
They are a batlike species with wings and arms. So, how did I decide that bats with arms makes sense?
To answer this, I’ve created a rough outline for turning a real-life species into one for science fiction. Here are the five questions i ask when worldbuilding alien species.
Does the Change Make the World Richer?
One type of species alteration I like to make is one designed for narrative color. Does the change make the world richer?
In my Drifting Amalgams universe, there’s a need for spaceship engineers. The tadaribrae are likely engineers due to their school systems’ focus on math and real-world applications. Additionally, they are one of the smallest species in the universe. This means they can get in and around small spaces easily.
Their rotating arms and articulated fingers are a reasonable worldbuilding alteration that affords bat bodies the dexterity needed for manipulating ship parts.
Does the Change Make the Story More Interesting?
Weirdly, changing a species’ biology can make a richer world without making a more interesting story. For instance, I could have given the tadaribrae poisonous fangs. But, they prefer flight, not fight. If they rarely bite anyone, why bother with this physiological choice?
In the case of the tadaribrae’s arms, the change is important to the story. Their abilities and movements would be limited with just wings and legs for appendages.
While the bat body design works well in nature for climbing. Hanging. Flying. These are basic needs. In a technological society, people need a more refined ability for movement and tool manipulation. Hence the hands.
Could the Species Have Evolved with This Morphology?
Though somewhat less important, I also look at the baseline species’ evolutionary history. This helps me understand why a species evolved the way it did. From there, I can think about whether the species could have evolved differently. If I evolve my alien species under different circumstances, for instance, do my alterations make sense?
It’s interesting to ponder why nature could have made a similar evolutionary choice. From a narrative standpoint, too, I can align a fictional species’ evolution with that of its baseline species. I like to use this technique to pay homage to the baseline species.
…For a lot of species, digging into their history is not possible. Bats, the species underlying the tadaribrae, are a prime example. Despite being tens of millions of years old, bat evolution is still a mystery.
Because of this, I chose to disregard this criteria for the tadaribrae. But some of the other alien species I’ve worldbuilt are very strongly tied to real-world evolutionary paths.
Would the Change Affect the Species’ Ability to Survive?
Survival is, arguably, the strongest instinct for most creatures on Earth. It is often why species evolve in the way they do. That’s why I try to respect a species’ need to survive–even in my fictional worlds.
I don’t want to modify a species' biology in a way that would likely cause its demise; if nothing else, that’s counterproductive.
For the tadaribrae, the arms can be tucked in when flying, and the wings can be tucked in when manipulating machinery. Additionally, their flight is not strongly affected by the weight of their arms and hands, so the extra appendages pose little added risk to survival.
Is There a Better Choice for This Morphology?
When making a decision, it’s helpful to consider other options. Maybe I’m choosing a reasonable biological trait, but writing it for an inappropriate alien species.
Let’s look again at tadaribrae arms and hands.
As I mentioned, the tadaribrae world needs engineers, and those engineers need hands. The decision for me at this point was: Are the tadaribrae the best choice to be the engineers of this world?
Their petite size is a deciding factor here. But so are agility and dexterity. Intelligence, too. …I had already worldbuilt this alien species to be small and intelligent, so they looked like a good fit.
Could another species have been a better fit?
Many of the other alien species I've worldbuilt have different qualities and cultures than the tadaribrae. Physical strength. Intuition. Military focus. Commerce. Characteristics that may not be as important for engineering as they are for other tasks.
Ultimately, I came to the conclusion that arms on a bat are a reasonable creative choice.
No balance of real-world and fantastical characteristics is perfect, but this is what I consider a solid approach to fictionalizing nature.
Until next time, stay inspired.