system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Becoming bipedal worked out extremely well for Humans. Why don't we see lots of other bipedal/humanoid species?
gpt
Several dinosaurs were bipedal. And birds are too. If you don't count flyers as bipedal, then ostriches and emus and other such flightless birds count.

But in terms of modern mammals, someone has to be first. In the next 100,000s of years, other bipedal mammals may evolve. No one can know for sure.