During warm periods in Earth's history, known as interglacials, glaciers the size of continents pulled back to reveal new landscapes. These were new worlds for early humans to explore and exploit, and 1.4 million years ago this was Europe: a Terra nullius unoccupied by humans.
That immediately reminds me the Indo-European expansion across Europe. It happened almost yesterday, in comparison with the article’s timeframe; “just” a few millenniums ago. But it seems that it was the same overall direction - Caucasus to Ukraine to the rest.
I really like the explanation of the dating method, as people assume that carbon-14 is used for everything. (It’s a bad idea to use it for anything older than 60ky)