"more evolved" means what, exactly?

"It is time to stop thinking we are the pinnacle of evolutionary success – chimpanzees are the more highly evolved species, according to new research," New Scientist reports today, in an article headlined
Chimps 'more evolved' than humans.

In this chip-on-the-shoulder perspective, the research offers yet another good reason for humans to rationalize the countless cruelties – casual, benign, and otherwise – that we inflict on these beautiful and intelligent, Earthlings of the nonhuman persuasion.