if a different species was going to inhabit earth how long roughly would it take?

Question: if a different species was going to inhabit earth how long roughly would it take?
- Keywords:
  Earth,
  inhabit,
  species
Asked by anon-174178 to Alex, Carl, Melanie, Tim, Yewande on 20 Jun 2018.
- Alex Seeney answered on 20 Jun 2018:
  
  That’s difficult to answer. Potentially never – if we think back to life before humans, when the dinosaurs roamed the Earth, no intelligent life (i.e. something comparable to the human race) developed during that time. If you wanted something similar to humans, it would likely take a few million years for such a species to evolve.

Question: if a different species was going to inhabit earth how long roughly would it take?