The (theoretical) combination of two prokaryotes into a single eukaryote could be seen as reducing the information
and
it changes complexity, either increased or decreased
Razd,
So it would be safe assuming that diversification is reaching a less complex/less chaotic/more ordered system. That is fine by me since entropy in the Universe increases but not necessarily that on Earth.
the DNA is some 500x's the human genome
Be careful when associating length of dna with complexity, most of dna is non-coding or "junk-dna".