Complex sentence: Around 6000 BC, when people began to domesticate animals and plant wheat and barley, the number of settled communities increased, particularly in the eastern Zagros mountains, and handmade painted pottery appears.
Split into simpler sentences: Around 6000 BC, when people began to domesticate animals and plant wheat and barley. The number of settled communities increased, particularly in the eastern Zagros mountains, and handmade painted pottery appears.