Darwin : Evolution of a Painter?

Today i took a trip into town to check out the Palazzo delle Esposizioni, particularly their new Darwin exebition. It interesting to see his drawing made as accurately as possible to then be able to use for scientific research. And ofcourse with darwin involved there started to be alot of mentioning of the evolution of animals in the world. How things change an adapt and most of all the survival of the fittest



Now as i stood there watching i started to ponder the evolution of an artist. How is starts by simple curiosity, and is evolved by the research and practice of tecnique. But as darwin states that only the fittest and best survive it seemed to clash with the art world. How many artist are there which are renowned world wide yet people look at them and say:
"My son could do that".
Is the evolution of the better artist defined by a greated ability in tecnique, in realism, in the development of the piece itself, or by the thoughs going through the artist as he paints.
It would seem that everything defies the very fundamental laws that our species followoed to arrive to this point.

Anyway in the end i just ended up with the question:
What does it mean for an artist to evolve?
If you get some good answers tell me cause it will be interesting to see different peoples thoughs

Here are some Links too:
http://en.wikipedia.org/wiki/Charles_Darwin
http://www.palazzoesposizioni.it/canale.asp?id=236