>>516695307
The Younger Dryas melt started 13,000 years ago and ended 8000 years ago. For 5000 years oceans worth of water would melt on the three mile tall glaciers and flood the land mile high floods for weeks at a time. This happened over and over for 5000 years until the glaciers were gone. At the beginning of the Younger Dryas coastlines went out to the Continental shelf and sea levels were 400 feet lower. Under these conditions it would be impossible to have any sort of civilization besides paleolithic hunter gatherer. But it is entirely possible that more advanced civilizations existed prior to the Younger Dryas. If they did, they did, they would have been coastal, and their remains are now hundreds of miles out to sea under 400 feet of water.