Actually, it does BOTH.
A common creator in the sense that naturally genes are very similar in the sense that the original design for life on earth followed the same basic pattern - so if you want to believe that this is due to God choosing that basic pattern you certainly can.
As far as the genetic similarity indicating the development of the species since the original creation of life on earth (ie, "the dreaded 'E' word"), well, it certainly does that too.
One need only examine the developmental stages that early human embryos go through (showing fish, then reptilian, and finally mammalian features) to get a clue - one would HOPE (against hope) at least....
What percentage would suggest a different creator or different ancestry?