  This paper investigates cultural dynamics in social media by examining the
proliferation and diversification of clearly-cut pieces of content: quoted
texts. In line with the pioneering work of Leskovec et al. and Simmons et al.
on memes dynamics we investigate in deep the transformations that quotations
published online undergo during their diffusion. We deliberately put aside the
structure of the social network as well as the dynamical patterns pertaining to
the diffusion process to focus on the way quotations are changed, how often
they are modified and how these changes shape more or less diverse families and
sub-families of quotations. Following a biological metaphor, we try to
understand in which way mutations can transform quotations at different scales
and how mutation rates depend on various properties of the quotations.
