Isn't it obvious that sitting for prolonged periods of time is completely unnatural? We have evolved to run, jump, climb, not spend 8 hrs a day compressing our spines - it is only in the last 100 or so years that sedentary occupations have become the norm
First, have you ever seen cheetahs? Even in their natural environment, they laze about almost all day.
Second, we are intrinsically lazy, and not because "the modern world has corrupted us".
Notice I am not claiming that our bodies were in fact designed to sit forever, but can we really declare it is "obvious" that sitting for a long time is against our nature?
From an evolutionary standpoint, it makes sense that we would preserve energy. Food wasn't always plentiful, and unnecessary calorie burning would work against survival and propagation of the species.
Sure, that will happen at some point. Don't hold your breath though; evolution works over extremely long timescales (hundreds if not thousands of generations)
The evolutionary pressure of people dying at 65 instead of 66 (completely made up numbers) is pretty small, especially in a modern society where their dependents will not usually starve as a result.
