Fossils alone may
intrigue us, but we still yearn to see "fleshed-out" portraits of our ancient ancestors.
Creating these images takes a wealth of scientific insight and a touch of artistic
license.
Before attempting to put flesh on the bone, it helps to understand
whether an individual was male or female, young or old, tall or tiny. Clues to all of
these traits can be found in fossil remains.
Teeth reveal roughly how old a person was at death. In children,
molars may not have emerged. In adults, the wear on teeth provides a rough estimate
of age, and various diseases may have taken their toll on both teeth and bones.
Certain bones of the hands, feet, arms, and legs also indicate age because they develop
in sections that fuse together as a child grows.
Fossils for males and females often differ, particularly in a
species like Lucy's that is sexually dimorphic: Males are much larger than their
mates, and their fossils are marked by deeper muscle scars. The pelvic bones of males
and females may also be distinctive; females often have a wider "pelvic inlet" (the
bony part of the birth canal) that is adapted for giving birth.
Body size is estimated from weight-bearing bones, including those
in the hips. In Lucy's species, Australopithecus afarensis, the average adult male
weighed near 110 pounds and stood around 4 feet 11 inches tall. Adult females were
relatively petite, weighing roughly 60 pounds and standing only about 3 feet 5 inches
tall.
To get a sense of facial characteristics, a well-preserved skull
is invaluable. But such skulls are rare. In the early 1980s, anthropologist Tim White
pieced together hundreds of fragments from different individuals to form a complete,
yet composite skull. In 1992, the discovery by anthropologist Yoel Rak of a fairly
complete skull at Hadar validated White's work.
With a forward-jutting jaw, low-sloping forehead, and heavy brow
ridge, this creature likely had a face more like a gorilla's than like a human's
today.
Taking their cues from the fossils, paleoartists have depicted
A. afarensis as decidedly ape-faced. These artists -- whether sculpting in
clay or sketching on paper -- rely on a detailed knowledge of anatomy to put muscle
and flesh on fossil bones.
For one of his works, sculptor John Gurche started with a cast of
the 1992 Hadar skull. Layer by layer, he added muscles of modeling clay and plasticene,
using muscle attachment scars on the fossils as a guide. He crafted pockets of fat
tissue and salivary glands to fill out the face. He shaped epoxy into nasal cartilage.
Finally, he covered his creation in a pliable urethane "skin," inserted acrylic eyes,
and added hairs one by one.
Paleoartist Jay Matternes, when working in two dimensions, also
painstakingly "layers" muscle, cartilage, and skin onto the fossil skeletons in a series
of progressive sketches.
Many traits leave no fossil clues and are left to the discretion of
the artist. The size and shape of soft tissue parts, like the tip of the nose, the ears,
and the breasts, as well as skin color and hair density, are a matter of artistic license.
But stunning portraits by such renowned artists as Gurche and Matternes are by no means
flights of the imagination. They are grounded in science, and they provide a glimpse into
our distant human ancestry.
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