The big news in the journal Science tomorrow is the discovery of the oldest human skeleton—a small-brained, 110-pound female of the species Ardipithecus ramidus, nicknamed “Ardi.” She lived in what is now Ethiopia 4.4 million years ago, which makes her over a million years older than the famous “Lucy” fossil, found in the same region thirty-five years ago.

Buried among the slew of papers about the new find is one about the creature’s sex life. It makes fascinating reading, especially if you like learning why human females don’t know when they are ovulating, and men lack the clacker-sized testicles and bristly penises sported by chimpanzees.

One of the defining attributes of Lucy and all other hominids—members of our evolutionary lineage, including ourselves—is that they walk upright on two legs. While Ardi also walked on two legs on the ground, the species also clambered about on four legs in the trees. Ardi thus offers a fascinating glimpse of an ape caught in the act of becoming human.

The problem is it is doing it in the wrong place at the wrong time—at least according to conventional wisdom, which says our kind first stood up on two legs when they moved out of the forest and onto open savanna grasslands. At the time Ardi lived, her environment was a woodland, much cooler and wetter than the desert there today.

So why did her species become bipedal while it was still living partly in the trees, especially since walking on two legs is a much less efficient way of getting about?

Zinjanthropus has changed quite a bit in appearance since this species was found 50 years ago. Art by Peter Bianchi © National Geographic.

Fifty years ago, Louis and Mary Leakey discovered the remains of Zinjanthropus boisei, a member of the human lineage researchers now call Paranthropus boisei or Australopithecus boisei.

National Geographic ran a story on the discovery of "Zinj" in 1961. It was hailed as a missing link. Now we know that this species was an evolutionary dead end. It may be that it was too specialized, in this case for heavy chewing. Big teeth and massive jaw muscles may have been the wrong thing to invest in, as opposed to big brains, for instance. 

Pharaoh Tutankhamun's skull defines his general appearance. Its anyone's guess what his skin color was. This particular model (right) was prepared from a CT-scan-based "cast" of his skull (left) without knowing its identity. Reconstruction by Michael Anderson. Photos in composite © 2007 Michael Anderson and Mark Thiessen © 2007 National Geographic Society.

I’ll never forget attending opening night of the King Tut exhibit in Los Angeles in June 2005. As I approached the exhibit entrance with Elisabeth Daynes, the French sculptor who created a likeness of King Tut for the cover of National Geographic magazine, we passed a patch of animated demonstrators whose placards read “King Tut’s Back and He’s Still Black.” A few steps further I was informed by other National Geographic staff attending the event that Dayne’s sculpture, which she had traveled from Paris to see on display, was out of the show.

I was disappointed, but not surprised. Every time the magazine’s art department attempted to depict ancient Egyptians, we received letters complaining about their appearance. This was despite every effort of talented artists and hard-working researchers to be accurate and fair. For the King Tut reconstruction we went to the extreme of commissioning a second model by a team that was not informed of the identity of the skull cast we provided. Their results confirmed that the cover image was as reasonable as forensic reconstructions of individuals can be. One can quibble about the shape of Tut’s nose and ears, and the color of his eyes and skin, but hard bone determined his general appearance. Judging from the demonstrators outside the exhibit in Los Angeles, we were once again unable to please everyone.

The reasons for this dissatisfaction are complex. Confusing notions about ‘race’ and a concern that scholars ignore Africa’s contribution to civilization seem to be at the heart of it. There is still some debate about the skin color of ancient Egyptians, but most experts agree that, from Alexandria in the north to the Sudanese border, ancient Egyptians would have looked much as they do today.

Our story about ancient Egypt’s 25th dynasty in the February issue of National Geographic provides an opportunity to look again at questions about the appearance of ancient Egyptians and whether Egypt’s, ergo Africa’s, contribution to civilization has been ignored. If you’d like to comment on our story or this topic, here’s the place.

Before you respond on the skin color issue, I recommend that you review how scientists currently view race at http://www.understandingrace.org.

In the current issue of Nature you’ll find a much-awaited report on the bodies (as opposed to the heads) of the folks that lived at Dmanisi in Georgia (the former Soviet Republic) about two million years ago. The report was much-awaited because only the heads of four of the individuals discovered there have been thoroughly reported. That left many of us wondering what their bodies were like.

We knew their brains were small and early estimates of their height and weight showed they were small in body as well, but we didn’t have a good sense of their body proportions or skeletal details from the neck down. And the reason why we cared about their bodies so much was that a paradigm was about to be broken.