OK..My Bad, I thought they had said over 14 thousand.
Then, it must have been the underwater thingy by Japan I mistook that for. Anyway, they had to figure out how long ago the water level was below that one to even begin to determine how old it was..or one of those...cant remember now.
There's an initial melt starting at the peak of the great ice sheets which is 20,000 years back. That beach lasted about 8,000 years. Then, there's a level typical of 14,000 years back when most of the Great Asian and North American sheets had melted. Then there's another level at 12,000 when there was a loss of a combination of high mountain glacial fields, residual but otherwise quite thin ice sheets ~ maybe only a few hundred meters high, and run off from Antarctica.
Then, there's the Younger Dryas. Something happened to cause the freeze to resume in the Northern hemisphere and in a short period the ice age started up ~ but without as much accumulation of ice. The dates for that are from 14,500 and 12,200 years BP for about 1300 years ~ ending just about when the Temple structure in Turkey started.
Even then the ocean continued to rise until 8,500 years ago ~ and has risen little since that time ~
Whatever our ancient distant ancestors were doing usually took place in prime land filled with wild game and great numbers of nutritious plants. That territory is mostly along rivers and stretches off into the delta lands where the water flow slows down and provides year round water to the plants.
As the ocean rose it covered those lands. At the same time there was suddenly far less alluvial soil and no doubt human beings suffered from the loss of food of the most preferred types.
Over the last 8500 years we have succeeded in moving up off the riverbanks into the foothills and even the mountains. That's why there are so terribly many of us around these days.