Now an equally
appealing discovery had been made. Scientists excavating in
the dusty Middle Awash region of Ethiopia have unearthed an amazingly
complete skeleton of a new species of hominid -- an ancestor to
modern man -- which they have named Ardipithecus ramidus,
The find began in 1994 with the
unearthing of a hominid hand. One and a half decades later, Ardi was
revealed in her full form, a skeleton consisting of over 125 bone
pieces. Among the most complete hominid skeletons found to
date, Ardi is approximately 4.4 million years old, 1.2 million years
older than the famous "Lucy" (Australopithecus
afarensis) skeleton. Ardi is in fact the oldest hominid
found to date.
Ardi is an irresistibly appealing find to
most. It provides unprecedented insight into how humans and
apes diverged from a common ancestor approximately 7 million years
ago -- closer to Ardi's time than we are to Ardi's. And the
discovery reveals a shocking revelation -- Chimpanzees and other
close ape relatives might actually have evolved more radically than
humans did over that 7 million years.
Kent State University
anthropologist C. Owen Lovejoy, a member of the Middle Awash team,
states, "This skeleton flips our understanding of human
evolution. It's clear that humans are not merely a slight
modification of chimps, despite their genomic similarity."
is closer to humans than chimps. Measuring in at 47 in. (120
cm) tall and 110 lb. (50 kg), Ardi likely walked with a strange gait,
lurching side to side, due to lack of an arch in its feet, a feature
of later hominids. It had somewhat monkey-like feet, with
opposable toes, but its feet were not flexible enough to grab onto
vines or tree trunks like many monkeys -- rather they were good
enough to provide extra support during quick walks along tree
branches -- called palm walking.
However, most of Ardi's time
was spent upright on the ground. Long dexterous fingers
showcase Ardi's humanlike characteristics; its wrists were also more
flexible than apes. These features helped it to catch things on
the ground and carry objects.
Another surprise comes in Ardi's
environment. Ardi lived in a lush grassy African woodland, with
creatures such as colobus monkeys, baboons, elephants, spiral-horned
antelopes, hyenas, shrews, hares, porcupines, bats, peacocks,
doves, lovebirds, swifts and owls. Fig trees grew around much
of the area, and it is speculated that much of Ardi's diet consisted
of these figs.
The surprise about the environment is that it
lays to rest the theory that hominids developed upright walking when
Africa's woodland-grassland mix changed to grassy savanna.
Under this now theory, hominids began standing and walking upright as
a way of seeing predators over the tall grasses. The discovery
of Ardi -- an earlier upright walker that lived in woodland --
greatly weakens this theory.
Scientists have theorized that
Ardi may have formed human-like relationships with pairing between
single males and females. Evidence of this is found in the
male's teeth, which lack the long canines that gorillas and other
non-monogamous apes use to battle for females. Describes
Professor Lovejoy, "The male canine tooth is no longer
projecting or sharp. It's no longer weaponry."
still debate over parts of the creature's skeleton. In
particular, the pelvis was smashed and had to be extensively
reconstructed using digital technology. According to Penn State
paleoanthropologist Alan Walker, who was not involved in the
discovery, "Tim [White] showed me pictures of the pelvis in the
ground, and it looked like an Irish stew."
over 110 remnants discovered from over 35 other Ardi's and a complete
skeleton, the find is undeniably exciting. States Professor
Walker, "[Ardi is] a lovely Darwinian creature. It has
features that are intermediate between the last common ancestor and
And Professor Lovejoy adds, "When
we started our work [in the Middle Awash] the human fossil record
went back to about 3.7 million years. This isn't just a
skeleton; we've been able to put together a fantastic,
high-resolution snapshot of a period that was a blank."