system
Given the following post, respond as if you're commenting on Reddit:
human
[Time Travel] Why is it that killing one bug in the past (usually prehistoric times) would alter the entire Future?

**Update**: Realistically, Bugs always get stepped on since the dawn of time even before dinosaurs and caveman.
gpt
If a time traveler stepped on say, a butterfly, think about the plants that the butterfly would have landed on, or the animal that was going to eat it. The future is changed ever so slightly, a few flowers don't get pollinated and never bloom; a lizard goes hungry and has to wander farther from its nest to find food. 

These small changes set off a few *big* changes, instead of mating and passing on its DNA, the lizard runs into a predator and gets eaten, and many species of lizards wind up not existing. The flowers never bloom, and a large chunk of plants as we know then today never wind up evolving. 

The changes, small at first, start adding up. Before you know it, there's giant chain reactions. Animals that were supposed to live, *don't*. Things that were supposed to get eaten, *aren't*.

Many things may wind up similar or even the same as they are today, but the changes will be noticeable. The entire alphabet may wind up different, if people even wind up creating the same languages at all. If (somehow) the people you know *do* wind up existing, they may be totally different, the country you live in may wind up a terrifying mirror of what you once knew. Life may not be worth living once you realize the breadth of the changes you caused with your carelessness. 

All because you had to hunt a t-rex.