This is an interesting TED talk on the human conception of beauty, and where it comes from.
Not surprisingly it comes from evolution. Any living thing that can exhibit a preference based on some form of stimulus would form the basis for the concept of beauty.
The punchline of the talk is that beauty is the appreciation of something done well. I have to agree with this, and it is not just limited to the art world. There have been quite a few instances in my life where I have observed engineering done well and it moved me to tears. When a complex project is undertaken which incorporates planning, work, effort and skilled manufacturing, and it all works as it should giving the results we expect, then it is a work of art. I have experienced the feeling of great joy when a system I have been a part of developing works. I don't know if others feel the same way, but I like a good, filled-in checklist that shows all of the tasks have been completed. There is an aesthetic to have all of the boxes filled, just so.
I have heard it argued from some that our humanity is diminished if we acknowledge that it is all a product of random chance and chemistry that is below our conscious selves. There is the sense that we don't deserve the enjoyment or appreciation we get if it is not sourced from a conscious action, be that from ourselves or from some deity that gets all of the credit.
Strangely enough, it does not lessen the joy I feel for things done well even if I do know that it is the product of evolution, and the automatic mixture of stimulus and brain electro-chemistry that gives the sense of pleasure or contentment. In fact, thinking about it that way is also a form of beauty; we are machines ourselves, so complex that we even have consciousness. Knowing the source of feelings in no way diminishes them.