Some years ago I saw and interesting article in "The National Geographic" about the excavation of a 50 foot high mound in Bulgaria. The pottery from 6,000 BC was bright and varied, and artistically interesting. Later pottery from 3,000 BC was dark and dull, although well shaped. At the time I wondered, what happened to the earlier people to bring about such a change. This was before I learned so many interesting things that could have had an influence. I wish I knew the date on that article, as I have a large collection of National Geographics, organized by year.
Take a look at the July 1980 issue
"Take a look at July, 1980 [National Geographic]."
Thanks, I'll check it out. Meanwhile, here are some further thoughts on emerging knowledge of earlier than expected social/civic development.
For a long time in North American, archeologists were limited by the Clovis first prejudice. Now they are finally discovering that Indian cultures existed well before the Clovis period. Presumably this occurred shorthly after the Ice Age began its end around 18,000 years ago (18kya). In France and Spain, archeologists were surprised to discover that some of the best cave art dated back to around 32kya. This makes sense as during the 20kya period there was a significant, stepped downturn in temperatures.
Since man tends to build communities along the coast, for fishing, boating, and sunbathing ;) the fact that sea levels were around 400 feet lower at the end of the Ice Age, means that probably a lot of development was drowned as the sea levels rose over the millenia. The Persian Gulf above the Straits of Hormuz was drowned around 8kya, so who knows what civilization might have existed there. The Sumerians may have been the recovery phase of this disaster which they memorialized in the flood story of Gilgamesh (Noah). Since the Syrian city was far above sea level, it does not surprise me that it could exist as a well developed commercial center that survived by not being inundated.
If schools of archeology were not so hidebound, a lot more undersea exploration would be taking place, discovering who knows how many wonderful secrets. Anyone interested should check out the books and web site of Graham Hancock who has done a lot of exploring of this topic.