Science has already shown that Lucy is NOT a human ancestor, but closer to a gorilla.
See
http://www.pnas.org/cgi/content/short/104/16/6568
Also see
Announcing the “Lucy" Summer Tour
They've also suggested that the "man/ape split" (sounds like a painful dance) occured millions of years before Lucy. (See
Skeptical of "Teeth" Speculation). Basically, they are grabbing for anything these days.