Either Binford's or Jacob's model fit the nuclear zone notion. Permanent villages of the Plains Town Phase appeared There was the use of the microliths in sickles, eventually being replaced by metals at the end of the Neolithic. Intensive Cultivation began at 5500 until around 3000 BC People grew bread wheat, six-row barley, lentils, grass peas, linseed, cattle, pigs, dogs, all with minimal irrigation. Civilizations followed as we know them from historical records and archaeology. Each nuclear zone is similar, but with local adaptations.
Irrigation seems to be an important step toward urbanization.
But there is some dispute about whether domesticated plants are needed for urbanization to start. Many have suggested that if urbanization is defined as large populations living in an aggregated settlement, then that may have happened in many areas before domestication. In North American eastern woodlands, Joseph Caldwell defined Primary Forest Efficiency with groups having populations of 1000 or more in a settlement without agriculture. Made possible by a particularly rich natural environment. In areas of the Middle East, it may have been a matter of control of certain resources such as obsidian, lapis lazuli, bitumen and accompanying trade that allowed large populations to grow.