one million b.c.

Like forensics experts working on a case that went cold hundreds of thousands of years ago, archæologists are discovering that equipped with the next generation of genetic sequencers that there able to find bits of ancient hominid DNA when sifting through the sediment of practically any old cave.
No fossil evidence nor artefacts, though surely that’s pretty exciting to uncover, is required to trace how our direct ancestors and Neanderthal cousins spread across the continents and perhaps interacted. Surely this can be expanded to the whole of the plant and animal kingdoms, as well.  I wasn’t expecting that our machines were so finely calibrated to detect biochemical markers as so faint a trace, but this is sure to be revolutionary as palæontologists have already managed to extrapolate and reconstruct whole monstrous dinosaurs and more modest primogenitors of our kind out of just a fragment of a tooth or a little toe bone.