It was one of the most productive terrestrial ecosystems on the planet, and the grazing and browsing animals that lived in it were the food base on which the Yana community depended.

The seasonal rhythms of the Mammoth Steppe were extreme.

Summer in this region at 70 degrees north latitude means continuous daylight for weeks at a time — the sun circling the sky without setting, providing near-continuous light and warmth.

The growing season is short but intense.

Plants rush to grow and seed before the cold returns.

Animals graze through the long days, building fat reserves for winter.

Winter is the opposite: weeks of near-total darkness, cold that in the Pleistocene may have been significantly more severe than modern Arctic winters, and the challenge of finding food when the steppe is frozen.