In his book Guns, Germs and Steel, Jared Diamond explains why the transition from a nomadic hunter-gatherer lifestyle to settled farming was such a major shift in the human story. Once humans learnt to farm, they could put down roots, both literally and metaphorically. Once they were able to grow food instead of having to forage for it, they were forced to organize themselves better, develop specialized tools and skills to use them, and learn to rely on fellow humans. As these agricultural communities grew, people began to differentiate themselves by the skills they had and roles they performed, forming guilds and ‘caste’ groups based on these. This gave rise to the complex modern society that we inhabit.