Ardipithecus Ramidus - Ardi - Oldest Skeleton of Human Ancestors

Author: Ardi
Published: 2009/10/12 - Updated: 2017/05/10
Topic: Blogs / Writings / Stories - Publications List

Page Content: Synopsis - Introduction - Main

Synopsis: Discovery of Ardi a relatively complete Ardipithecus ramidus fossil skeleton sheds light on human evolution.

Introduction

On October 1, 2009, paleontologists announced the discovery of a relatively complete Ardipithecus ramidus fossil skeleton. The fossil is the remains of a small-brained 110 lb (50 kg) female, nicknamed "Ardi".

Main Item

The bones of Ardi were actually first discovered over 15 years ago, but only recently have been assembled enough to where a firm hypothesis on her life can be made.

Ardipithecus ramidus was discovered in Ethiopia's harsh Afar desert at a site called Aramis. Radiometric dating of the layers of volcanic ash encasing the deposits revealed that Ardi lived 4.4 million years ago. She had an ape-like head and opposable toes that allowed her to climb trees easily, but her hands, wrists and pelvis show she strode like a modern human and did not knuckle-walk like a chimp or a gorilla.

The fossil sheds light on a previously poorly-known stage of human evolution more than a million years before Lucy (Australopithecus afarensis), the iconic early human ancestor who lived 3.2 million years ago, and which was discovered in 1974 just 46 mi (74 km) away from Ardi's discovery site.

The skeleton of an early human who lived 4.4 million years ago shows that humans did not evolve from chimpanzee-like ancestors, the common ancestor of both humans and modern apes was different from both, and apes have evolved just as much as humans have from a common ancestor. Genetics suggest that humans and our closest living relatives, the chimpanzees, diverged 6 million to 7 million years ago, although some research suggests this may have happened 4 million years ago.

Researchers infer from the form of her pelvis and limbs and the presence of her abductable hallux, that she was a facultative biped: bipedal when moving on the ground, but quadrupedal when moving about in tree branches. Ardipithecus ramidus had a more primitive walking ability than later hominids, and could not walk or run for long distances. Her brain, while small, is positioned in a way more similar to that of Australopithecus and modern humans, suggesting more human-like visual and spatial perception.

"The novel anatomy that we describe in these papers fundamentally alters our understanding of human origins and early evolution," said project anatomist and evolutionary biologist, Professor C. Owen Lovejoy, Kent State University.

"These are the results of a scientific mission to our deep African past," said project co-director and geologist, Dr. Giday WoldeGabriel of the Los Alamos National Laboratory.

Project co-director and paleontologist Professor Tim White of the Human Evolution Research Center at the University of California Berkeley adds, "Ardipithecus is not a chimp. It's not a human. It's what we used to be."

Because of this amazing find, we can now conclude that humans did not evolve from apes but were a totally different species.