This new (published online a week ago) research should interest some here. It's about biochemically resurrecting ancient genes and testing their functions in modern organisms in order to find out how increases in complexity in the "molecular machines" of cells came about long ago (in this case, 800 million years ago).
Here's the abstract in Nature, and here's an article in
Science Daily.
In this case, a gene duplication is involved, then the two copies specialize and also deteriorate so they cannot perform each other's functions. In this way, they both become essential to the new version of the "machine", and cannot be removed without destroying it. That should be interesting to those who like discussing the idea of "irreducible complexity", because it indicates one way in which "I.C." machines could be built up step by step through evolution.
™ Version 4.2