How long have humans been walking the earth?

Question: How long have humans been walking the earth?
- Keywords:
  Earth,
  human,
  walk
Asked by anon-174139 to Alex, Carl, Melanie, Tim, Yewande on 20 Jun 2018.
- Alex Seeney answered on 20 Jun 2018:
  
  If by human, you mean Homo sapiens, then about 315,000 years. We are constantly finding new evidence and reanalysing old theories, so that number may change.

Question: How long have humans been walking the earth?