As ancestors, they were shown as extremely modern looking; as evolutionary dead ends, they became stooped, beetle - browed cretins. (newscientist.com)
The other group is thought to have represented late «archaic» humans (Neanderthals), a supposed evolutionary dead end (Journal of Human Evolution, vol 25, p 393). (newscientist.com)
«Being unable to combine beneficial mutations from different individuals and unable to purge progressive accumulation of deleterious mutations, they are expected to represent evolutionary dead ends.» (newatlas.com)