An important piece of context is that food organisms were way more abundant during this time in human history, than they are now. There was almost no need to ca

An important piece of context is that food organisms were way more abundant during this time in human history, than they are now. There was almost no need to carry food because the environment was so densely populated by plants and animals that humans could eat. That was true on land and in the ocean, and it made long voyages way less physically difficult than our modern approaches to backpacking or sailing, where the weight, volume, or cost of food creates a limiting distance before resupply.