The author didn't even differentiate us as having only two legs. Humans can stand tall and can see over greater areas than say dogs, and keep better watch for t

The author didn't even differentiate us as having only two legs. Humans can stand tall and can see over greater areas than say dogs, and keep better watch for threats, opportunities and escape routes. Because of our brains and hands, we can cultivate and domesticate (observing seasons) so as to prepare and store food in advance for easier survival and longevity, giving us time to think about other things and move beyond subsistence. We can also move between great temperatures zones by using clothes. We can also navigate with the aid of maps and use fire to cook so that meat is easier to digest, thus being able to have a multi-use digestive tracts. This means having a greater nutritional range so that a more complex organism can evolve and giving us access to a greater array of possible food. Domesticating dogs meant we could sleep for longer periods while the dogs could warn us of wild animals or scare them off: good for REM whilst travelling over long distances and thus unable to build fences.