Yes. I literally and actually believe that the hundreds of millions of Jew and Arabs around the world sprang from one person 4000 years ago. Call me back whenever you've had a reality check.
It is mathematically feasible. Actually, no - it's mathematically likely.
There are people who are alive today who can look upon hundreds of their own descendants (children, grandchildren, great-grandchildren, etc). And that's within an 80-year-period or so.
Population growth is exponential.
Of course, I wouldn't expect you to understand that.