Imagine: An alien planet filled with plant-equivalent and animal-equivalent life, like ours.
Except there are no animal-animal carnivores. How is this possible? If an animal kills/eats another, it is destroyed by the other animals.
Let’s call it “Mutually Enforced Protection”. (MEP). Pheromones released by death send every life form nearby into a revenge-frenzy, preventing carnivorism.
Like this hornet which kills a bee in its hive. https://www.reddit.com/r/NatureIsFuckingLit/comments/l3yf20/bees_kill_a_giant_hornet_with_heat_generated_by/
All of their energy goes into competing with each other by non-lethal means. Eventually this leads to intelligence and civilisation.
In their alien cultures, the brutality of carnivorous species and murder is unheard of and outrageous.
Now imagine that MOST planets have developed MEP, but Earth hasn’t.
Some planets develop civilisations, advanced enough to travel space, make contact with other space civilisations as well as discover ‘wild’ planets like Earth.
Earth was a surprise discovery. They soon discover Earth-life lacks the pheromones they’re used to, and when something is killed... almost inconceivably... nothing happens. No MEP reaction. Animals kill each other all the time.
Earth is considered one of the most brutal planets in the galaxy, the planetary equivalent of a dog-fighting pit. Not just because of the slaughter of factory farms by humans, but of nature itself.
After discovery, Earth attracts the most unscrupulous civilisations as spectators. Their favourite arenas are war zones, favelas, and for the nature-inclined, the African savannah.
They are fascinated by the brutality and violent competition, which is so foreign and ...different.
Slowly at first but then all at once, a black market appears for Earth-life.
Gladiatorial arenas are built all over the galaxy to pit Earth species against each other. Elephants vs humans, venomous snakes vs lions, polar bears vs Siberian tigers, and of course, humans vs humans.
The vastness of the galaxy and it’s appetite for exotic and violent Earth-life is a seemingly infinite pit that threatens to take all of Earth’s life for its new arenas.
//Earth’s population depletes, and the capture of ‘wild’ Earth species becomes illegal. Still, illegal wildlife trafficking booms.
Breeding programs and advanced genetic engineering techniques produce hybrid species, and soon the number of ‘humans’ and other Earth-life housed in captivity exceeds their wild populations.
Civilisations discover that they can resolve political disputes in a way previously inaccessible to them. Warfare, with engineered Earth-life as it’s weapon.
An arms race develops between major powers, each competing to breed the most numerous and violent Earth species in their new armies. Soon most planets host a substantial Earth-life army.
As tensions reach their height, the unexpected happens. Revolts of Earth-life break out across the galaxy.
Lacking the capacity for violence themselves, the civilisations are caught off guard. Arming themselves with technological superiority, the civilisations attempt to weaponise their MEP against the Earth-life.
But after billions of years of non-violence, their capacities are dulled and cannot compete against the now genetically-engineered and hyper-violent Earth-life.
Ultimately, Earth-life wins out, unifying multiple civilisations into the first galaxy-spanning Empire, and Earth becomes the first galactic capital in the Earth Empire.
//Earth is fortified with alien technology and begin rebuilding the depleted biosphere...
Obsessed with violence, the new Earth Empire pools the resources of multiple now-defunct civilisations to reach the previously unreachable.
A fleet of raiding ships packed with warriors, to our neighbouring galaxy... Andromeda.