The creatures escaped. We selected them to breed fast. Perhaps too fast. The customers were always hungry for the newest model.
At first, it was just small beasts. Dog-sized. The kind a child could raise instead of a dog or a cat. More intelligent than a dog, and more loyal than a cat.
Then the zoos got in. Suddenly, having natural animals was passe. Visitors wanted to see titans - enormous, scaley creatures with rows of teeth that could crush a car on accident. T-rexes, Triceratops, Stegosaurus...but then we moved on to animals nature had never even seen.
New monsters were being created by the week. Magazines held contests to name entire artificially created species (though that ended rather quickly after a new sea reptile was named Draconia MacDracoFaciem).
But amidst all the excitement and optimism of this new age of genetic recombination, we never considered what would happen if a breeding pair escaped...
I am making a post-apocalyptic world where the cause of the disaster is some sort of genetically created invasive organism. This civilization is so adept at genetic manipulation that, rather than splicing sections of DNA from one organism onto another, they can custom create a new creature from scratch with the same ease as making a 3d model for a video game. At first, the corporations with this technology used it to make real-life Pokemon - cute, fuzzy things ranging in size between a cat and a golden retriever and market-tested to compete against them. The yellow text above goes on to say how zoos realized they could make a real-life Jurrasic Park, and later realized they could make real-life Monster Hunter Park, but I'd like to focus on that last line.
You see, while those T-rexes and wyverns and Gore Magalas survived and thrived after the event, the menageries they were kept in (zoos came to refer to facilities that held naturally-occurring animals) were just too spread out for a single escape to result in the collapse of all civilization. No, the real cause of the end of the world was the little Neo-housepet things. While the genomic technology is versatile to create literally anything that can breathe and grow, it takes a long time to create a single animal. To create enough stock to sell these things like Pokemon cards, the brilliant corporations in charge of this tech engineered their housepets to breed very rapidly. Of course, this meant that they spread like weeds once they got out, especially without any natural predators.
And this is where I get stuck. I'm not sure how to go from this to "civilization is boned." I don't want to make these rats crave the blood of humans because I still want there to be humans after this disaster. But I want the rats - or whatever they unleash - to devastate modern infrastructure with little to no warning. The dinosaurs/dragons can help this disaster along - when the national guard is helping victims of a flood caused by rodents chewing through the wires at a dam, it's hard to get them out and fighting a rampaging T-rex - but the primary cause is the rats. I need help with what these animals do and how they cause the apocalypse.
- Despite being called "rats" for now, they range in size from about the size of a rat to as large as a dog. Most consumer models have similar features to many quadruped mammals (2 eyes, hair, tail, ect), but any of those features can be played with.
- This setting plays loose with the boundary between magic and science. For now, let's say that any adaptation that occurs on a real-life animal, such as armored calcite plates, electric-generating organs, or bioluminescence can be put on this rat.
- As stated, the escaped dinos and dragons can help the collapse of civilization along (most likely by destroying nearby centers of population and the knowledge therein), but the rats have to be the primary culprit in the apocalypse.