There have been some attempts to study language drift over time and geography. The proponent that springs to mind is Joseph Greenberg. His work is an attempt to

There have been some attempts to study language drift over time and geography. The proponent that springs to mind is Joseph Greenberg. His work is an attempt to work backwards to the common core of language, the starting place. If you knew approximately how fast language changed, and you saw two related languages, you would know when they drifted apart. There are also linguistic isolates like Basque where you can't really play this trick.