It seems like a stupid thing to say, doesn't it? But alas, you did say it in post 14.
So, Norwegians and Bangladeshis, if kept separate for millions of years, could wind up after that time as different enough from each other to constitute different species.
In post 14 you said "Speciation occurs when populations or sub-populations are isolated (genetically) from their sisters and brothers over a long period of time." There's no "could" there. You did not say 'species could be formed when... ' Previously, in post 14, you said you knew how species were formed. Now you say you don't know.
So, my question is, why do you think Bangladeshis and Norwegians are becoming seperate species? Do you have a particle of evidence to support that strange assertion?
I hope this helps.