The curious thing is that the Black Sea wasn't there 8 to 9 thousand BP. The Mediteranean didn't break through into the Black Sea Basin till around 7 thousand BP.
A lot of people are beginning to gues that the true source of the Indo European peoples was under the present Black Sea.
So9
"A lot of people are beginning to gues that the true source of the Indo European peoples was under the present Black Sea."
You got it. The Black Sea flood (Noah's Flood) 7,600 years ago changed everything. At that time the whole region was very arid, people were crowded around the fresh water Black Sea as fishermen and irrigation farmers, most were farmers. (The sea edge and the river valleys were the only places liveable)
When the 'plug' at the Bosporus broke, the water in the whole Black Sea began to rise at the rate of six inches a day and covered the villages around the edge under 550 feet of salt water. Most survived and were able to walk away with what they could carry and their animals.
The survivors streamed up the river valleys of the Don, Dniepier, Danube and others shoving out or killing the valley inhabitants before them. Remember, the river valleys were the only inhabitable areas now (fresh water) because the Black Sea is becoming salt water, everyone's world changed.
These refugees streamed into Europe bringing farming and the language with them. They streamed across the Anatolian Plateau to become the Sumerians (Gilgamesh), Egyptians (pyramid builders) and others. They set out across the steppes where they were recently discovered as mummies in China (Tocharians) and some even believe they are the Ainu of Japan(I don't). They are also the Aryians who invaded Northern India.