At it's most primitive level of development, agriculture that involves planting seeds of specific plants, and husbanding specific resources useful to those plants can work provided there's a bit of water around ~ in areas that need not be much different than raw desert.
Hunting and gathering, however, require a MUCH MORE DEVELOPED environment with a mix of forests, glades, wide varieties of plants of all types good for diverse animals species, etc. In short, your basic desert is not terribly useful to hunters and gatherers ~ ask the Papago Indians about that ~ they were the FIRST to meet and greet the Spanish missionaries in California ~ and they quickly assimilated since they could easily see hunting for lizards and roots was a lot harder work than hanging around with a bunch of Catholic priests who seemed to know what they were doing, had nice clothes (from China no less), and who ate quite well. (NOTE: Only modern people suggest that moving from hunting and gathering to settled agriculture damaged the Papago people as "individuals". Sure, it destroyed their society, but if you want to go track down lizards for dinner, go to it eh).
Consider, the first Western Europeans out of the Franco/Spanish refugia headed due North securing prime "seal" hunting grounds all the way to the Arctic Ocean. Agriculture has yet to penetrate Northern Norway in fact, and the greater part of the population descends from the earliest hunter/gatherers to get there. (NOTE: gathering is rather limited to seaweed, lingonberries, moss and various roots which means the name of the game was primarily hunting with seal skin being the primary source of vitamin C.)
As the Ice Sheets withdrew they left behind grasslands or desert, but it took centuries for the full forest ecology to develop. The Middle Eastern agriculturalists could move into what were for that time "marginal lands" and prosper undisturbed!
This is consistent with events back in their Anatolian and Assyrian homelands. There the most ancient "temples" reveal that the locals seemed to not know anything about lions, sabertoothed tigers, or the sort of large game such critters need to survive. So far the biggest cat carving found seems to be that of something about the size of a bobcat or lynx.
The big dogs, so to speak, were off chasing game in the grasslands ~ and that's where our own hunter-gatherer ancestors tried to make a home.
Myth of the Hunter-GathererOn September 19, 1997, the New York Times announced the discovery of a group of earthen mounds in northeastern Louisiana. The site, known as Watson Brake, includes 11 mounds 26 feet high linked by low ridges into an oval 916 feet long. What is remarkable about this massive complex is that it was built around 3400 B.C., more than 3,000 years before the development of farming communities in eastern North America, by hunter-gatherers, at least partly mobile, who visited the site each spring and summer to fish, hunt, and collect freshwater mussels... Social complexity cannot exist unless I it is supported by a productive subsistence economy.
by Kenneth M. Ames
Archaeology Volume 52 Number 5
September/October 1999