According to her discoverers, Ardi's frame combined both ape-like and human-like characteristics. Her skull had a primate look and a small brain, as well as teeth that included a pair of small canines. Though her feet had a thumb-like big toe that enabled her to grasp tree-limbs, her pelvis and femurs were shaped towards walking upright. Her fingers and flexible wrists were also much like ours, making it impossible for her to knuckle-walk on all fours, like most primates do.

How They Found Ardi

In 1994, paleoanthropologist Tim White and his field team were working in those desert hills when an Ethiopian member of the team spotted the first shattered bits of what turned out to be a nearly-complete fossilized skeleton. It was located in an area where fragments of dozens of other Ramidus individuals are also eroding out of the dry, crumbly, many-layered hills. The intact skeletons of ancient humanoids known to science number perhaps five, so this one was viewed as a priceless treasure.

For 15 years, White's international team painstakingly reconstructed the skeleton, identified it as female, and pored over it with forensic intensity. They gave her the nickname Ardi. It's an Ethiopian word for "ground," a tribute to her apparent nature as a ground-dweller.

If they're right, Ardi lived around 1.2 million years earlier than "Lucy," another African humanoid that was heretofore viewed as our oldest known upright-walking ancient relative. Ardi may or may not be a direct human ancestor. Scientists are still looking for an earlier creature that may have lived at the fork where primates and pre-human creatures parted company in the evolution timeline. But according to White's team, Ardi looks to be more closely related to humans than to chimpanzees, with whom some scientists have previously insisted that we are genetically related.

In other words, critters who walked upright on two legs may have had their own branch of evolution much earlier than scientists thought.

Old Theories Out the Window

According to White's team, Ardi's discovery radically rewrites the accepted history of our human emergence.

Prior theories put our ancient ancestors in grassy savannahs in east Africa, where they supposedly had no trees to climb, and started walking upright in order to see over the tall grasses. But Ardipithecus fossils are found in a region that is also rich in fossils of ancient trees and forest-dwelling animals. In fact, Ardi's feet, with their splayed-out big toes, might have made it hard for her to run very far or fast. She wouldn't have lasted long on the savannahs, without a handy tree to scramble up, in case of predator attack.

To be sure, there are some evolutionists who disagree with White's team on their reading of Ardi's's bones. These arguments will doubtless last until that older fossil is found.

Heterosex in the Crosshairs

Meantime, White's team wades boldly into theorizing about Ardi's sex life. Their theories start with her teeth. Most early primates had (and their direct descendants still have) two large fangs, or canine teeth, which males use freely in their social infighting and aggressive sexual behaviour towards females.

But Ardi's canines are much smaller. So her discoverers speculate that pair bonding may have been developing -- that Ardi's kind may have been more in control of the mating process than other early primates. Females of her species may have been selecting for males with smaller canines, leading to gradual decrease in the fang size. The New York Times commented drily that Ardi is becoming "another of science's Rorschach tests...on which particular points of view can be agreeably projected."

One heterosexual question that White and his team didn't tackle is a big one: when did evolution bring emergence of our human-style breeding cycle? Wild primates, and many non-primates as well, have breeding cycles that are seasonally regulated, to ensure that young are born during the time when food is abundant in their environment. Some mammals are timed to have just one birth during a solar year.

But humans today can give conceive and give birth in any month of the year, including the dead of winter, even in northern climates. This variation may have developed as a result of our emerging power to create technology -- to ensure a baby's survival by creating a comfortable environment, complete with stored food, at any time of the year.

Out in Prehistory?

Ardi's discovery also pushes back the possible horizon of homosexuality, bisexuality and gender-identity questions -- back to 4.4 million years ago.

For some years now, we gay people have been avidly collecting scientific evidence of all kinds of animal homosexuality, from penguins to horses, hoping that it would help us in our battles for acceptance. Most to the point, for evolution politics, is what primates do with same-sex attractions.

According to Canadian anthropologist Paul L. Vasey in International Review of Primatology, "Available data indicate that this behavior is phylogenetically widespread among the anthropoid [higher] primates, but totally absent among prosimians [lower primates]. ...For a substantial number ...it appears to be a more common pattern under free-ranging conditions."

In 2004, even the National Geographic earnestly went looking for data on this fascinating subject -- and found female macaques happily engaged in what we'd call lesbian lovemaking. Also, according to the Geographic, "The bonobo, an African ape closely related to humans, has an even bigger sexual appetite. Studies suggest 75 percent of bonobo sex is nonreproductive and that nearly all bonobos are bisexual."

Result: the naturalness of animal homosexuality and bisexuality is now abundantly on record. It has even been used as evidence in some court cases, by plaintiffs looking to overturn state sodomy laws. Robin Dunbar, an English professor of evolutionary psychology, says, "The bottom line is that anything that happens in other primates, and particularly other apes, is likely to have strong evolutionary continuity with what happens in humans."

Reproduction Isn't Everything

Gender variations may also have found their footing along that early horizon.

In much of the animal world, the nature of genetic sex and sex chromosomes is way more complicated than it is with humans. Most primates have the same XX/XY system that we do. But science has learned that a certain percentage of animals, like some humans, are born with intersex variants of what would be the normal sex-chromosome configuration for that species. As with humans -- intersex people who are XXY, or XYY, for example -- these variations often result in an individual animal that doesn't reproduce sexually.

Yet in an animal society, such individuals are not bullied and hounded out into the outer darkness. Instead, they share in the life of their species' biomass, and contribute to its collective survival and well-being in other ways besides passing on genes. As a member of a grazing herd, such an individual forms part of the protection-in-numbers factor. They can help influence their environment in important ways, like grazing on certain plants, fertilizing with their manure, spreading seeds that get caught in their coats or tails. In a wolf pack, an infertile female or male wolf can still play a vital role by hunting and helping to care for the alpha pair's pups. In a band of free-ranging humanoids like Ardi, perhaps the non-reproducing female could serve as an "auntie."

This question has been seriously discussed by science, as in Frances D. Burton's article in the Dutch journal Acta Biotheoretica, titled "Ethology and the development of sex and gender identity in non-human primates."

Drawing Conclusions

Bottom line: survival and development of a species, through millions of years, isn't just driven by heterosexual reproduction.

Evolution is a grand dynamic that is moved along by a great many smaller dynamics that are in constant play with each other. In the world of wild animals, homosexuality, bisexuality and gender variety are clearly part of the grand dynamic. Along with heterosexuality and reproduction, it is rainbowed into the "good of the whole." Far back in evolution, these diverse behaviours must have rippled through all of life in ways that we are only now beginning to see.

Only among Homo sapiens, in recent eons, have we seen the emergence of a fierce objection to full participation of "non-heteros" in the social life of some (not all) societies. Only among humans is there such a focused attempt to isolate -- even to cruelly destroy -- the homosexual, bisexual or gender-variant individuals on grounds that "they don't reproduce." It's chilling to note that strict Christian creationism is the creation of a religion that aims to crush and obliterate all non-heterosexual and non-gender-conforming members of our society.

Maybe that's one of the reasons why creationists hate us so much. Not only do they interpret the Bible literally on the growth of life on Earth, but they also interpret the Bible literally on sexual behaviour of all kinds. If creationists are ever forced to admit that evolution really did happen over many millions of years, they'll also have to admit that they themselves -- along with the rest of us -- evolved out of those ancient landscapes where a whole range of sexual behaviours was not only natural -- but also part of a global dynamic in which all creatures moved ever onward, into their future.

Indeed, creationists might be confronted with the fact that they carry genetic traces of that contribution in their own DNA. They might owe their personal existence to that positive complexity and richly textured support that all the different sexual orientations brought to their shared moment on that great time-line -- one where little Ardi took her first steps on two feet.