Alien worlds teeming with cliches can be dangerous for even the most skilled authors and space explorers. Especially since it seems like nearly every alien world consists entirely of man eating monsters or chest bursting parasites. But don’t worry. It’s not a stand up fight, but just another bug hunt. Just be sure to ditch your space helmet. You won’t need it as we design an alien ecology for our story!

My Honest Thoughts on Alien Ecosystems

The biggest misstep when it comes to designing a fictional ecological system is simply not having one at all. I get why. Biology can be very boring for most people and, like a lot of sciences, very hard to understand. I blame our public education system for taking a subject that is actually fascinating and somehow finding a way to make it boring.

I suppose the real question is should a writer detail the ecosystem their story takes place in? Only if the audience is going to spend a lot of time there, especially if a good portion of the plot takes place in the wild. If the main characters are only spending a few chapters or scenes in the alien wilderness, then creating an entire ecology is a wasted effort. Video game developers I think could benefit the most from fleshing out their ecologies. I always hated how wolves would attack the player character with suicidal determination. Predators will usually only attack humans because the predator is either starving or is defending its territory or young from the perceived threat the human represents. Using more realistic or varied predator behavior could be used as a gameplay mechanic forcing the player to not just fight against monsters, but understand the creatures in the game and how they relate to the environment.

If a story isn’t going to take place in a single area it still does help to at least consider the environment when designing monsters, even one off beasts who attack the heroes. That way an author doesn’t wind up with a cold blooded lizard monster laying siege to the protagonist’s ship that crashed in the arctic. As for examples on how to do an ecology properly, I can think of a few works.

Dune is the big one. Interestingly, Dune looks like one of those impossible single biome planets I complain about, but in Dune’s case the local fauna are the ones responsible for shaping the environment. In this case, the book takes a fairly standard science fiction cliché, and explores it as a concept. The environment of Dune also shaped Fremen culture, creating a society of hardened survivors. The sandworms of Dune are sustained by smaller creatures that live in the sands, filtering them out as it moves. The worms are also intensely territorial, justifying their attacks upon the main characters (or at least their spice harvesters).

Another interesting fictional ecosystem is in Brandon Sanderson’s Stormlight Archive series. Yes I know. I am a Sanderson fan boy. I can’t help it. I like how he writes his action scenes. In the Stormlight Archives, the world of Roshar is constantly hit by hurricane like superstorms. As a result, most animals are arthropods with thick carapace they can retract into. Even the plants have adapted by retreating into hardened sheaths or otherwise finding ways to hide when they sense an oncoming storm. The cultures there have adapted as well. Cities were built into areas naturally shielded from high winds. It is a surprisingly well thought out ecological system when most fantasy authors usually go for the whole “It’s magic. Don’t think about it too much.” approach.

War Against The Chtorr is an interesting example. This is a book series about an alien ecology that is invading earth. I love the concept. David Gerrold spends a lot of time fleshing out the complex symbiosis and interconnectivity of his imagined alien ecology. He also plays up the horror angle, showing how terrifying it would be to face down alien life. While I am not so excited about his lackluster creature designs and Heinlein inspired philosophical rambling, the core concept and story remains highly fascinating. Look it up, but be careful. The books have some rather questionable content in them and it is not for children or teens.

System Shock 2, an old video game, finally did hive minds justice with its depiction of the Many. The part I love about it is how the victims of the Many react to being part of a hive. Some infested humans beg for death screaming “Kill me!” as they attack you. Other people are like “I love being part of something bigger!”. For some, being part of a hive mind gave them a clarity of purpose than they never had in life. I find this fascinating because one person’s heaven can be another person’s hell. The Many itself really tries to sell itself to the player as well. It tries to justify its consumption of humanity as something good and even has a few legitimate points. Those are undermined by a lot of its victims begging for euthanasia of course, but the contrast between the Many’s lofty claims of moral superiority spoken in a mesmerizing chorus of voices and its obvious body horror make for a very memorable presentation.

Finally, for those who might want to take a crack at creating a fictional ecological system, I can leave a few tips to get them started, though I encourage extra research in this area. Holly Lisle has a short article about designing ecosystems. Even watching nature documentaries can serve as useful inspiration.

J.P. Beaubien’s Crash Course in Ecology

Let’s start with the cool stuff first. Apex Predators. First, apex predators always have smaller populations compared to their prey. Most predators also prefer weakened prey. Even powerful predators are very good at risk assessment as even a minor injury in the wild could result in death. Also, a lot of predators will scavenge, especially if the corpse is fresh or there is a lack of prey in the area. Large predators can be territorial. Even large predators can also hunt in packs, but the larger the predator, the more food it requires, the less advantage there is in hunting in packs. A lot of predators will also use ambush tactics with some relying exclusively on ambush tactics. Frequently neglected are omnivores and they can be just as scary. Most bears are omnivorous and tend to be very territorial as they need a large grazing area to sustain their numbers. Also, even large herbivores can be very aggressive and territorial.

Prey animals have a number of defenses to use against predators from sheer mass to poison. Smaller prey tend to use the ‘have a crap ton of offspring’ tactic. Hopefully, a few of the offspring will survive into adulthood while most will fall to predation, sometimes even from their own siblings. Some opt for the opposite strategy where they use armor or weapons. In which case they often get into an evolutionary arms race of sorts with predators. Herding or schooling behavior is also a highly effective defense mechanism as a predator, or any creature, can only track so many entities with its sight as once. Having a large herd confuses the predator’s targeting system. However, herds and schools are only possibe in large open areas, hence why you don’t see as many herds in jungles or forests. Herds also need a lot of open grazing area to feed. Life needs food. Growing takes time and burns energy. The faster the growth and the bigger the size, the more food is needed.

Also, don’t neglect scavengers. Poor scavengers. No one ever thinks about them in fiction unless they need some ravens or crows for death symbolism. I really think there needs to be more highly intelligent scavenger species in fantasy and science fiction.

Parasites are almost always specialists. A parasite that quickly depletes its hosts’ population will not be a successful parasite for long. This is why when parasites jump hosts it proves devastating. Often the new hosts’ immune system response is what kills both the parasite and the host. Many parasites often have complex life cycles and some will even have multiple types of hosts for each life cycle.

Finally, when designing an ecology, don’t forget to show the symbiosis between various life forms. Most complex ecologies exist in a state of delicate balance. When that balance is thrown off, nearly every life-form in the ecosystem is impacted. An ecology can be a delicate thing.

If you want to get really advanced, consider going into some of the basic chemistry differences like silicone based life. This would also include playing with atmospheric conditions and gravity. A light gravity world is going to favor flight, heavy gravity is going to favor thick skeletons. What about a world with acid for oceans? What about a world with extreme temperature differences between night and day? That would be interesting. That could be a planet with two wildly different ecological systems that are active at different times. There are a lot of possibilities for new ideas.

Or you can just glue some rubber bits on an actor’s forehead and call it a day. Stupid television budget constraints.