Estimates of ancient human populations can be misleading when they lean too heavily on DNA ancestry alone, because DNA traces direct surviving lines, not the full populations and branches that once existed.
From History: 66.04 Million years ago (K–Pg extinction)
At the K–Pg boundary, birds were already diverse, but most of that Late Cretaceous variety died out, leaving only a small toothless slice of the bird world to continue.
Radiometric dating such as Carbon-14 and Potassium-Argon is scientifically sound, but it’s true that scientists need to carefully rule out contaminants.
The split separates our ideas and the material world. To live in harmony with nature, embrace the idea that our rational ideas must be internally coherent, but only empirical contact with reality justifies belief.