Who says? As I said several times here already.
The best human packers, mathematicians and so on, along with theire software are competing on hptt://www.packomania.com to pack the circles as tide as possible.
A program based on EA, with no packing knowledge except that the circles must not overlap and must be squeezed on the smallest square - competes with them successfully. Holds many records.
Who else can?
Optimising using randomness is usually a missed opportunity to use intelligence.
I wrote an essay about this topic back in 2008: Intelligent design vs random mutations.
http://edge.org/conversation/infinite-stupidity-edge-conversation-with-mark-pagel
Random change, then a selection, says Mark Pagel. As I agree, here's the link.