system
Given the following post, respond as if you're commenting on Reddit:
human
ELI: If humans originated in Africa, how did we also develope on remote islands like Japan?

Did humans travel to japan in boats from china and after a while forget they came from the mainland and created their own origin stories? Or, if not, how did we get to japan?
gpt
The former. Humans radiated outward from Africa in several waves, and over time colonized pretty much every place that could support us. Sometimes they ended up in places that later became islands after sea levels rose, and sometimes they used rafts or boats. You can even use genetics to work out roughly how long ago different populations diverged and when they first arrived wherever they ended up.