I’m about 30% through writing the first draft of a sci-fi novel. It’s slow going for several reasons, one of which is that I want to get my extraterrestrials right. My goal is for them to feel alien, not just be humans in costumes. I’m not exactly writing Hard Sci-Fi, but I strongly favor worldbuilding grounded in logic. The main character is abducted from Earth and taken to a star system where the dominant life form is a people he can best equate with crustaceans. They aren’t actually Crab People, but it’s easier to categorize them like that. In the book, I will be mostly focused on this species’ current evolutionary state and cultures but I’ve been also thinking quite a bit about how their evolution resulted in the present creature.
Speculative Evolution is a fascinating field that combines biology, paleontology, and speculative fiction (science fiction in my case) to imagine how life forms could evolve in different environments or under alternative circumstances. It seeks to envision alternative evolution of life on Earth or possible life on other planets, often exploring how different evolutionary pressures might lead to new adaptations, species, and ecosystems.
I don’t have a background in biology or any other sciences besides computer science. Forgive me, I’m going to sin against nature.
The Crap People’s Planet
The planet is roughly the size and mass of Earth. To be frank, this is plot convenience. I don’t really want to spend time on my main character having to adjust to a dramatically different gravity. Likewise, the atmosphere is human-compatible so he doesn’t need to wear an EV suit, respirator, or have some other sci-fi solution.
A very notable feature is that it is a binary system. The stars are about 100 astronomical units (AU, the distance from Earth to our Sun) apart. The planet orbits the larger star at about 1 AU but because of the star’s temperature and size, it beats down slightly hotter than on Earth. During part of the year, nighttime is seldom truly dark. The secondary star is almost as bright as a full moon on Earth so when the planet is in between the two suns, it receives light from the distant sun.
I’ve given the planet 2 moons, one having almost as much gravitational effect as our moon does on Earth. The second moon is smaller and pulls less but still influences the tidal effect.
While the planet has a magnetosphere, it is not as strong as Earth’s resulting in higher levels of radiation making it to the surface.
The planet is roughly 80% covered in water. The vast majority of the biodiversity is in the oceans. The surface is mostly arid desert. Plant life is less diverse and sparse than Earth. I have some pockets of tropical life that appear in canyons and other geological features that offer some protection from the sun.
In short, where the planet isn’t ocean, it’s very dead.
Crab People -10,000,001 years ago
The pre-Crab People, let’s call them Arc Crabs (for Archaic Crab People), evolved in the warm oceans. Unlike their primate galactic neighbor, life on their planet was kept to the ocean where they were protected from the sun’s radiation and the planet’s hot climate. The Arc Crabs were tool users and already the dominant life in the sea but in the same sense that Neanderthal was. Spears are nice, but tigers and tiger sharks are still dangerous.
Some clever Arc Crab had the idea of burring their eggs on shore, just a few feet in from the high tide, to keep them safe from predators. A few distant cousins of the Arc Crab were still able to reach the eggs but egg predation plummeted and the Arc Crab population exploded.
One of their cousins got a bit jealous and spent about a million years getting better at going inland to steal eggs. In response, the Arc Crab put that cousin on the endangered list while also moving further inland in the same period. At this point, the Arc Crab started to get pretty comfortable out of the water. The surface was still terrible, but damp borrows on the coast proved to be comfortable places to return to when not hunting or gathering.
The Dawn of Aquaculture – 2,000,002 years ago
The modern Crab People take over using the classic technique of outcompeting and outright killing the competition. The Arc Crab goes extinct leaving only one dominant tool user in the sea. Crab People have colonized and reshaped the coastlines. Most of the population lived in bay villages using permeable rock outcroppings to allow the replacement of seawater while keeping the predators out.
One day, a gatherer Crab Person had the idea of making a bay to just grow a specific plant that wildlife liked to eat. They eventually succeeded in transplanting the plant and propagating it. Within a few centuries, other plants were being grown in controlled environments. Aquaculture even expanded into raising prey in bays and even floating net pens.
As the population grew alongside the expansion of aquaculture, more Crab People moved their residential borrows inland leaving the coasts for food production.
From the Stone Age to the Iron Age
The Crab People have a major hurdle that slows down their progression out of the Stone Age: accessible fuel. Petroleum and coal were abundant from ancient oceans but tapping efficiently takes technology the Crab People haven’t created. Without firewood, the leap from stone tools to the metal tools needed to get to the oil and coal is slow coming.
Motivated by fuel for heating and early cooking, the Crab People eventually make the metal tools that allow them to get more fuel that allows for more metal tools and… so on. The Crab People shuffle their way into the bronze age and run full speed into the iron age after sorting out the furnace.
Space, Consumerism, and the Age of Aquarius
Given enough time, the Crab People would have made it to the Space Age on their own barring global cataclysm. But in my story, they were interrupted during their equivalent of the Middle Ages by being handed advanced technology by a well-intentioned alien organization.
The Crab People experienced a sudden onset of consumerism and glut in a post-scarcity economy. The people moved even further inland and deeper into the ground using high-tech digging technology and electricity. It wasn’t all sunshine and rainbows. There were old feuds still smoldering and new culture wars to resolve, but for the most part, they are living in a golden age when my story picks up.
Speculate With Me
Join the conversation on Reddit to share your Speculative Fiction creations, your favorite aliens from media, or tell me how I’ve really messed up the science and should stick to my lane.