system
Given the following post, respond as if you're commenting on Reddit:
human
[ELI5] What chance is there that two humans with absolute no genetic connection in immediate family to have as close DNA similarity as identical twins do?
gpt
There is a lot of DNA that doesn’t change from human to human.  Despite that, each human’s DNA differs by about 6.4 million base pairs.  For any given pair to be the same is a 50/50 shot, so for all 6.4 million pairs to be the same would be like tossing a coin 6.4 million times and getting the same result every time.

The odds of this are so astronomically low that it’s basically 0.