Design vs Evolution in Technology
In grad school, I had a friend who was working on using genetic algorithms for chip design. Some of the chips were able to do all the logic of a simple ALU, but nobody was able to understand their internals. There were extra transistors whose output were not even used. But without them the system would not work. So the working theory was that the system was somehow dependent on the temperature increase caused by the seemingly useless transistors.
For those who don't know, the author Steven Jurvetson is one of the geekiest VC's.