The fact of the matter for now is that the divergence and diversity among the languages is what we have to work with. When more is understood, perhaps with some luck we can draw a finer bead on the question of time depth. However, for now, whether shallower or deeper, the relatively unknown age of human occupation in the New World solves none of the outstanding linguistic issues before us.

I've just learnt what that means.

"focus one's attention on a problem" and "completely understand or solve a problem"

I can understand this : completely solve a problem.

But, I can't interpret this : completely solve a problem of time depth.

What does that mean? Could it be a problem that will be solved as time goes by?


"deep time" refers to very long time scales, much longer than we, with our experience of time limited to one or two generations (lifespans), can easily appreciate or comprehend. "Time depth" thus refers to the time scales associated with the subject.

Here are some sample sentences:

Deep time is the concept that the Geologic time scale is vast because the Earth is very old.
Dinosaurs and fossils in general are the key evidence to understand the evolution of life and our planet in deep time.
Knowledge of climate change in deep time provides clues to the way in which our climate system works under extreme conditions.