The origin of laziness?

It is believed that laziness is a biological trait. A survival tool. In itself laziness is not necessarily a bad thing. People often see/hear the word 'lazy' as being a stigma and get defensive.

Imagine that you're a primitive human living in a valley 10000 years ago... The valley has all that you need. It is safe. It is free of hostile predators or rival tribes.

There would be no sense in going elsewhere. This is laziness. A desire to maintain the status quo. Not to change.

How many people exercise?

Consider all the people you know.
Do many of them exercise?
Of all the people in the world, how many actually exercise?
Humans are pretty lazy and the invention of cars, televisions and computers have made things far worse.