How much of you is actually you?

"It’s a statistic that belongs in the journalistic category of Too Good to Check," Tabitha M. Powledge writes of the assertion that 90% of the cells in a human body are non-human microbes. In her weekly science blogs roundup, Powledge reviews a bioinformatician's post on the origins of that factoid, and summarizes the debate over its accuracy. Also: Does some new research on transgenerational epigenetics in male mice mean Jean-Baptiste Lamarck was right after all?