But it does: http://en.wikipedia.org/wiki/Nuclear_transmutation

Star fusion does it every day.

Evidence that something exists is evidence that it is created.

Alchemy and AI are both a bit more culturally specific. I agree that seeing life on earth would not logically be inconsistent with extr-terrestial life existing. But that is not to say AI=ET.

if by alchemy you mean making gold from another element then it does exist. we just cant do it yet

We can. It involves particle accelerators and is mindbogglingly expensive.