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Ancient ancestor
climbed, walked
By Bruce Bower
An ancient member of the human evolutionary family has put what’s left of a
weird, gorilla-like foot forward to show
that upright walking evolved along different paths in East Africa.
A 3.4-million-year-old partial fossil
foot unearthed in Ethiopia comes from
a previously unknown hominid species
that deftly climbed trees but walked
clumsily, anthropologist Yohannes
Haile-Selassie of the Cleveland Museum
of Natural History and colleagues report
in the March 29 Nature.
To the scientists’ surprise, this creature lived at the same time and in
the same region as Australopithecus
afarensis, a hominid species best known
for a partial skeleton dubbed Lucy.
years ago, paving the way
for Lucy and her kin. Haile-Selassie’s discovery may
come from an Ardipithecus lineage that survived near A. afarensis for
hundreds of thousands of years before
dying out, notes anthropologist C. Owen
Lovejoy of Kent State University in Ohio.
As in gorillas, Ardi and the newly discovered hominid possessed short, curving big toes capable of grasping against
the second toe. Other toe bones from
Ardi and the new discovery formed
joints that enabled a two-legged stride.
“Haile-Selassie’s discovery highlights our lack of knowledge about
hominid feet,” says anthropologist Tim
White of the University of California,
Berkeley.
Eight foot bones
(shown in the outline of a gorilla foot)
found in Ethiopia
belonged to a human
ancestor that climbed
deftly but walked poorly.
ancestor that climbed
deftly but walked poorly.
Stone Age fire rises from the ashes
Early humans may have used controlled blazes for cooking
By Bruce Bower
A 1-million-year-old fire lit by human
ancestors has flickered back to life in
South Africa’s Wonderwerk Cave.
Microscopic plant ashes and burned
bone bits come from cave soil that previously yielded several dozen stone tools,
say archaeologist Francesco Berna of
Boston University and his colleagues.
A member of the Homo genus, perhaps
Homo erectus, made a fire that produced
those remains, the researchers write
online April 2 in the Proceedings of the
National Academy of Sciences.
Berna’s team says the finds provide the
oldest secure evidence for controlled fire
use. Although it’s unclear exactly how
A piece of charred bone a few milli-
meters across (indicated by arrow) from
South Africa’s Wonderwerk Cave offers
evidence of an ancient controlled fire.
members of an extinct Homo species used
this fire, the findings fit with an idea that
H. erectus began to cook food nearly 2
million years ago, the scientists propose.
fire relies on measurements of radioactive elements in soil that signal how
long ago dirt covered the burned material. Molecular characteristics of burned
bone fragments show they were heated
to about 500° Celsius, consistent with
a controlled fire of some kind, the
researchers say.
Several stone artifacts from the same
ancient soil display fractures produced
by heating during tool production.
Human ancestors were probably
responsible for the Wonderwerk Cave
fire, but fires were not produced regularly that far back in the Stone Age,
say archaeologists Wil Roebroeks of
Leiden University in the Netherlands
and Paola Villa of the University of Colorado Boulder. Remains of a hearth or
campfire area, where fires would repeatedly have been lit, have not turned up in
Wonderwerk Cave.
FROM TOP: Y. HAILE-SELASSIE/CLEVELAND MUSEUM OF NATURAL HISTORY; PAUL GOLDBERG
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