I don't think the point was about being able to travel some place or not, but being able to settle it. Even humans can travel to Antarctica but won't leave a tr

I don't think the point was about being able to travel some place or not, but being able to settle it. Even humans can travel to Antarctica but won't leave a trace there. Also, we're discussing prehuman civilisations so dismissing an hypothesis as being an "extraordinary claim" within this context is a bit weird.