[blaze33]

Remember when bacterias suddenly decided to artificially dump oxygen in the atmosphere on a global scale? Once toxic and artificial, now part of the natural air we breathe.

Anyway, Wittgenstein would probably dismiss the relevance of defining what's natural or artificial for the world is made of facts and not of things.

[SmirthsDAC]

True, but the Great Oxygenation Event took an extremely long time to effect most species though, and there are certainly exceptions, but that's just it, they're exceptions. Humans are pretty much guaranteed to introduce change (we are innovators/technologists to our core.)