[douche]

I always find it really interesting how thin the evidence is, in many cases, when some of these paleontological discoveries are announced. Somebody digs up a partial skeleton, or even sometimes a single, fractured bone, and bam, it's a new, previously undiscovered species. Then we get artists renderings and theories about how this long-dead animal lived. There are some great examples from dinosaur studies - Brontosaurus vs Apatosaurus (which it seems are not the same thing anymore, haha), or the initial discoveries of the Igaunodon.

I think the DNA work is interesting and somewhat more credible than purely physiological bone work, but I'd be skeptical to read into it too much. The article says they retrieved "1 to 2 million base pairs of ancient nuclear DNA" from fragments as small as 25-40 basepairs. Wikipedia tells me that humans have over 3 billion base pairs in their genome. Assuming the Sima hominid genome is somewhere within the same order of magnitude, they found less than 1% of the total genome. I'm not a geneticist, so I have no idea how they figured out how to piece those tiny fragments of 1% of the genome together in the right order, but it seems a thin branch to go out on to draw serious conclusions.