That reminds me of bismuth crystals:<p><a href="http://www.google.co.uk/images?hl=en&source=imghp&q=bismuth+crystal" rel="nofollow">http://www.google.co.uk/images?hl=en&source=imghp&q=...</a><p>I think that is a result of it being one of the few substances other that water that has a liquid phase that is denser than the solid.
See also MIT's work on this: <a href="http://projects.csail.mit.edu/emergentDesign/genr8/" rel="nofollow">http://projects.csail.mit.edu/emergentDesign/genr8/</a><p>This uses grammatical evolution, which is basically evolutionary computation guided by a grammar. The Maya plugin GENR8 was originally implemented is available for download on their website under an unclear license (assume it's restrictive).
I don't know what it is, but there is something kind of strange and gross about these sculptures. I'm not sure why I'm responding in that way, but I find them both fascinating and somehow disturbing, as though I'm seeing a little bit of the root of my own being, and it is mathematical and alien.