Security and the origins of agriculture
More likely explanations for the agricultural revolution are probably far less observable:
The crucial role of security for the history of farming may also shed light on the birth of agricultural in the first place. Hunter-gatherers were very knowledgeable about plants and animals, far more than the typical modern. It would not have taken a genius -- and there were many, as their brains were as large as ours -- to figure out that you can plant a seed into the ground and it will grow. There must have been, rather, some severe institutional constraints that prevented agriculture from arising in the first place. The basic problem is that somebody has to protect that seedling for several months from enemies, and then has to harvest it before the enemy (or simply a envious neighbor) does. Security and allocation of property rights between providers of security and providers of farm labor were the intractable problems that took vast amounts of trial and error as well as genius to solve in order for agriculture to take root.
This would also explain how agriculture could spread from a single innovation yet look like independent inventions in the archaeological record. There were at least eight centers of secondary innovations (e.g. crop and livestock domestications and agricultural tools) that look independent: the Middle East, China, India, sub-Saharan Africa, Peru, central America, eastern North America, and New Guinea. But they all occured within a few thousand years of each other, after at least 100,000 years of anatomically modern humans. During these millenia humans were without agriculture despite large numbers of microclimates and microecologies suitable for agriculture during that entire period.
This indicates the slow spread (with many failed attempts and, quite likely, many reversals) of a primary innovation necessary for the use of these secondary innovations. The primary innovation had to be primarily cultural rather than genetic because it came long after the out-migration from Africa c. 80K-40K BP and was taken up by many of the genetically diverse results of that out-migration. Given what we know about the importance of cooperation, institutions, and security to the productivity of human economies, that innovation which slowly spread and made agriculture possible was almost surely an innovation in the culture of cooperation. Alas, the spread of such an innovation in oral culture can be observed at best indirectly in the archaeological record.
This would put the origins of agricultural into the more general large patterns of history, the most important of which are based on the interaction between security and wealth.