The Desert Pastoral Nomads

There was widespread human settlement there between 15 thousand and five thousand years ago. The people who were herding the cattle at that time arrived about seven and a half thousand years ago,. And they were there for a couple of thousand years, until things became too dry. Some of them moved up into mountains like the hogar tebesti. Their descendants still there to day. But most of them migrated. They understood the ek of systems. They knew where to find grazed animals in this extraordinarily harsh environment with enormous success. i have the highest admiration for desert pastoral nomads, or semi nomads. They know what they're doing. Am i right?