David has alerted us to the phenomenon of two worms that have evolved backwards.-DAVID: My theory of increasing complexity from a mechanism in DNA is under attack.-I don't understand why backwards evolution should undermine your theory. Just as vestigial structures are those that are no longer needed, why shouldn't our friends the worms get rid of complexities not needed for current environmental conditions? That doesn't mitigate against other creatures becoming more complex, in accordance with their needs, does it? But I'm out of my depth, so perhaps you could explain the problem to us non-scientists.