Humankind’s Oldest Relative — To Date

Say hello to Ardi, humankind’s most latest archeological find that puts her into the ever-lengthening family tree of human beings.

“Ardipithecus” is 4.4 million years old, which makes it about 1 million years older than the previous oldest link in the human geneolgy, a unique find several years ago by the famous Leaky team which they dubbed “Lucy”.

Ardi, also a female, now has gained center stage since her find in 1994. Details about her are now coming to light after 15 years of research from teams across the globe funded mainly by the National Science Foundation, the Institute of Geophysics and Planetary Physics of the University of California, Los Alamos National Laboratory, the Japan Society for the Promotion of Science, as well as others. One of those team members is Tim White, the director of the Human Evolution Research Center at the University of California, Berkeley. He says that this find isn’t a chimpanzee nor is it yet “human” but is a hominid that is on that road to human development. According to White “This is not that common ancestor, but it’s the closest we have ever been able to come.”

“In Ardipithecus we have an unspecialized form that hasn’t evolved very far in the direction of Australopithecus. So when you go from head to toe, you’re seeing a mosaic creature that is neither chimpanzee, nor is it human. It is Ardipithecus,” stated White.

Australopithecus is a later human evolutionary development more closely associated with Lucy than Ardi. This newest link in the family gene-pool lived in what is now know as modern-day Ethiopia located in East Africa. According to geologists that area 4.4 million years ago was very wooded, almost forest-like with ample water and food supply. The fossil record of the area supports a wide variety of plant and mammal life, including Ardipithecus.

While the teeth of Ardi were more like modern day human teeth and could support flesh-eating, the grinding feature of her molars indicate that diet probably consisted more of fruits, berries and nuts than the flesh of other animals.

Here are are some of the other fascinating things uncovered about Ardi after nearly two decades of study:

Gluteal muscle attachment points for the hips and pelvis prove that she was capable of walking upright for extensive periods of time.

While her hands and feet were primed for walking among the vast tree branches that would have been common in her location, she wouldn’t have been as deft for the task as modern-day chimpanzees as her hand and feet bones were shorter, a bit more rigidly formed and not quite as agile as other primates, much like modern human hands, although her foot’s big toe was still extended like apes and used for grasping limbs. However, she would not have been able to glid swiftly among the branches like most primates. Her trek among the trees would have been more careful and studied without a natural flare.

While her teeth were more rounded in the back, her canine teeth were more similar to humans than chimps. And, while her diet may have been mostly fruits and nuts, along with other plant-life, her boney development indicates she was no stranger to a meat diet rich in protein.

[Headline photo from the Hulton Archives – Ardi artist’s rendition by J.H. Matternes]