system
Given the following post, respond as if you're commenting on Reddit:
human
[Numenera] Why are humans completely unchanged from their 21st-century forms?

Aside from the occasional abhuman or mutant, humans are exactly the same a billion years in the future from now in both appearance and manner of thinking.

Why? That's a long time to go without changing.
gpt
Speciation.

There are actually several species of "human" in a billion years. The one you are more familiar with is simply the only one called human.

Also, as an aside, evolution doesn't always actually make dramatic differences over time. It only puts a slight pressure toward those that survive and reproduce more effectively. If there is little to no such pressure, than a species changes very little. Think alligators.

Most humans in a billion years though are more attractive, stronger, and smarter than the equivalent human in 21st century forms. But being attractive, strong, or smart does not necessarily negate any of the philosophies we use in the 21st century. They're still all valid ways of thinking.