Recently, there have been some exciting discoveries and advances in the study of human evolution. Tim White and others have finally published information and analysis about Ardi, the nearly complete humanoid skeleton they found in Ethiopia in 1997. It has taken 12 years to fully analyze the find. Ardi is the oldest hominid skeleton ever found.
Ardi, a 3.5 foot female Ardipithecus that walked on two feet and lived 4.4 million years ago, predates Lucy by a million years. Some revelations about Ardi are that she did walk on two feet, and yet had feet which could also grip tree limbs. This makes bipedalism much earlier for hominids than thought. For whatever reason, bipedalism must have had a tremendous evolutionary advantage for primates that evolved into humans, since it is a poor way to amble. Scientists are theorizing that bipedalism freed the hands for carrying food. (I thought also perhaps for carrying infants) An upright position then paved the way for other advantages such as social interaction, tool use, and speech, and was reinforced.
Though I don't quite understand, Ardi also separates humans from the ape and gorilla branch more than once thought. Although we come from the same root as apes and gorillas, I guess the first hominid creatures developed on the hominid branch, not on the same branch as the gorillas and apes. They evolved separately. Still, we share 99.9% of the same genetic material as our primate friends. Another revelation is that Ardi has small teeth, unlike chimpanzees.