We still do not know the origin of the first supermassive black hole seeds. We are using observations of black holes in dwarf galaxies to try and understand the formation of the first black holes.
The occupation fraction of black holes in dwarf galaxies may tell us whether black hole seeds were made light or heavy
Amy Reines has been looking for black holes in dwarf galaxies using the SDSS. She is finding black holes in galaxies even smaller than those we found (Greene & Ho 2004, 2007; Barth et al. 2008.) Malte Schramm has been playing similar games with Chandra Deep Fields.