Why do we have so many wishes and desires? Two years ago I started to learn (as self-education) evolution theory and neurobiology
for to understand - who we are and where we came from?
Now I see clearly that we are our brains, which are the result of RNA &amp; DNA selection
and replication.

Many of the issues now resolved for me: about love and intuition, origin of religion and art etc.

But one question remains "a mystery":
why are there so many wishes, desires, urges?
What is the neurobiology base for a monstrous amount of consumer goods, objects of art etc.?

The most primitive idea is "complexity of brain -> intricacy of processes -> lots of desires".
Another naive answer has to do with so called "play-explore-investigation instinct",
which plays an important role when two basic instincts are "still".

But to me, human wishes and urges look like more of a  Akkerman function 
than just "a lot of".

I belive that (sooner or later) evolution and neuroscience will give answers to all questions 
about our mind and behavior.
So glad to hear something about this one!
In the context of evolution, desires and dreams (beyond the lower tier of Maslow's Hierarchy) could be seen as, not an adaptation, but a spandrel of the adaptation of consciousness.  

Consciousness allows us higher cognitive skills, particularly the ability to reflect on events and predict events through modelling, which allows us to modify our behavior in a succesful way.   But this extra predictive power also gives us an imagination with which we can imagine ourselves in a better position to exploit our dopamine centers (seek pleasurable activities that don't propagate the species).