Cogito-
I'll try to be brief. Capitalism is roughly 400 years and came about after the industrial revolution in europe.
Selling goods for profit is not sufficient for an economic system to be 'Capitalist'. You are referring to mercantilism. You could argue that mercantilism was proto-Capitalist in that it has a profit motive, but it was certainly a very different from modern Capitalism as we know it.
You've gone one worse, though, because you've even claimed that bartering is Capitalism, so you even left out buying and selling for profit. Bartering is not Capitalism.
I think your problem is that you're confusing Capitalism with trade. Trade has existed since man had any surplus material - basically since agriculture.
Capitalism is something quite different. Here is a brief outline of the differences:
public.wsu.edu/~dee/GLOSSARY/CAPITAL.HTM
In any case, my point was that Capitalism is not a 'natural' system like the weather. It is an economic system of human creation, just as slavery, surfdom, and mercantilism were.
When humans have no more use for Capitalism, they were invent new means of engaging in economic activity - this is happening already, and has happened throughout history. Eventually, a new dominant mode of economic activity will take the place of Capitalism.
Given the amount of pollution, climate change, food and water scarcity, tonnes of junk we produce and the periodic crisis that we're experiencing under Capitalism with greater frequency and intensity, I'd say that change will come about within the next few decades.