That the Jomon had the leisure to create their pots before these changes happened suggests they were smarter and more settled than archaeologists had realised.
The latest discovery pushes the dawn of the Jomon era in Japan back 3, 500 years to a period when glaciers were rampant in much of the northern hemisphere.
But the leisure and sedentary existence that the Jomon would have required for their pottery have generally been supposed to result from climatic changes at the end of the ice age.