Oldest Evidence of Stone Tool Use and Meat-Eating Among Human Ancestors Discovered: Lucy's Species Butchered Meat





Pics at the citation showing marks


http://www.sciencedaily.com/releases/2010/08/100811135039.htm


Oldest Evidence of Stone Tool Use and Meat-Eating Among Human
Ancestors Discovered: Lucy's Species Butchered Meat


These two bones from Dikika, which have been dated to roughly 3.4
million years ago, provide the oldest known evidence of stone tool use
among human ancestors. Both of the cut-marked bones came from mammals
-- one is a rib fragment from a cow-sized mammal, and the other is a
femur shaft fragment from a goat-sized mammal. Both bones are marred
by cut, scrape, and percussion marks. (Credit: Dikika Research
Project, California Academy of Sciences)

ScienceDaily (Aug. 11, 2010) — The evolutionary stories of the Swiss
Army Knife and the Big Mac just got a lot longer. An international
team of scientists led by Dr. Zeresenay Alemseged from the California
Academy of Sciences has discovered evidence that human ancestors were
using stone tools and consuming meat from large mammals nearly a
million years earlier than previously documented. While working in the
Afar Region of Ethiopia, Alemseged's "Dikika Research Project" team
found fossilized bones bearing unambiguous evidence of stone tool use
-- cut marks inflicted while carving meat off the bone and percussion
marks created while breaking the bones open to extract marrow.

The bones date to roughly 3.4 million years ago and provide the first
evidence that Lucy's species, Australopithecus afarensis, used stone
tools and consumed meat. The research is reported in the August 12
issue of the journal Nature.

"This discovery dramatically shifts the known timeframe of a game-
changing behavior for our ancestors," says Alemseged, Curator of
Anthropology at the California Academy of Sciences. "Tool use
fundamentally altered the way our early ancestors interacted with
nature, allowing them to eat new types of food and exploit new
territories. It also led to tool making -- a critical step in our
evolutionary path that eventually enabled such advanced technologies
as airplanes, MRI machines, and iPhones."

Although the butchered bones may not look like particularly noteworthy
fossils to the lay person, Alemseged can hardly contain his excitement
when he describes them. "This find will definitely force us to revise
our text books on human evolution, since it pushes the evidence for
tool use and meat eating in our family back by nearly a million
years," he explains. "These developments had a huge impact on the
story of humanity."

Until now, the oldest known evidence of butchering with stone tools
came from Bouri, Ethiopia, where several cut-marked bones were dated
to about 2.5 million years ago. The oldest known stone tools, dated to
around the same time, were found at nearby Gona, Ethiopia. Although no
hominin fossils were found in direct association with the Gona tools
or the Bouri bones, an upper jaw from an early Homo species dated to
about 2.4 million years ago was found at nearby Hadar, and most
paleoanthropologists believe the tools were made and used only by
members of the genus Homo.

The new stone-tool-marked fossil animal bones from Dikika have been
dated to approximately 3.4 million years ago and were found just 200
meters away from the site where Alemseged's team discovered "Selam" in
2000. Dubbed "Lucy's Daughter" by the international press, Selam was a
young Australopithecus afarensis girl who lived about 3.3 million
years ago and represents the most complete skeleton of a human
ancestor discovered to date.

"After a decade of studying Selam's remains and searching for
additional clues about her life, we can now add a significant new
detail to her story," Alemseged notes. "In light of these new finds,
it is very likely that Selam carried stone flakes and helped members
of her family as they butchered animal remains."

The location and age of the butchered bones from Dikika clearly
indicate that a member of the A. afarensis species inflicted the cut
marks, since no other hominin lived in this part of Africa at this
time. These fossils provide the first direct evidence that this
species, which includes such famous individuals as Lucy and Selam,
used stone tools.

"Now, when we imagine Lucy walking around the east African landscape
looking for food, we can for the first time imagine her with a stone
tool in hand and looking for meat," says Dr. Shannon McPherron,
archeologist with the Dikika Research Project and research scientist
at the Max Planck Institute for Evolutionary Anthropology in Leipzig.
"With stone tools in hand to quickly pull off flesh and break open
bones, animal carcasses would have become a more attractive source of
food. This type of behavior sent us down a path that later would lead
to two of the defining features of our species -- carnivory and tool
manufacture and use."

To determine the age of the butchered bones, project geologist Dr.
Jonathan Wynn relied on a very well documented and dated set of
volcanic deposits in the Dikika area. These same deposits were
previously used to determine Selam's age, and they are well known from
nearby Hadar, where Lucy was found. The cut-marked bones at Dikika
were sandwiched between volcanic deposits that have been securely
dated to 3. 24 and 3.42 million years ago, and they were located much
closer to the older sediment. "We can very securely say that the bones
were marked by stone tools between 3.42 and 3.24 million years ago,
and that within this range, the date is most likely 3.4 million years
ago," says Wynn, a geologist at the University of South Florida.

Both of the cut-marked bones discovered at Dikika came from mammals --
one is a rib fragment from a cow-sized mammal, and the other is a
femur shaft fragment from a goat-sized mammal. Both bones are marred
by cut, scrape, and percussion marks. Microscope and elemental
analysis using secondary electron imaging and energy dispersive x-ray
spectrometry demonstrated that these marks were created before the
bones fossilized, meaning that recent damage can be eliminated as the
cause of the marks. Additionally, the marks were consistent with the
morphology of stone-inflicted cuts rather than tooth-inflicted marks.
Dr. Hamdallah Bearat from the Ira A. Fulton Schools of Engineering at
Arizona State University determined that one cut-mark even contained a
tiny, embedded piece of rock that was likely left behind during the
butchering process.

"Most of the marks have features that indicate without doubt that they
were inflicted by stone tools," explains Dr. Curtis Marean from the
Institute of Human Origins at Arizona State University, who helped
with the mark identifications. "The range of actions that created the
marks includes cutting and scraping for the removal of flesh, and
percussion on the femur for breaking it to access marrow."

While it is clear that the Australopithecines at Dikika were using
sharp-edged stones to carve meat from bones, it is impossible to tell
from the marks alone whether they were making their tools or simply
finding and using naturally sharp rocks. So far, the research team has
not found any flaked stone tools at Dikika from this early time
period. This could indicate that the Dikika residents were simply
opportunistic about finding and using sharp-edged stones. However, the
sedimentary environment at the site suggests another potential
explanation.

"For the most part, the only stones we see coming from these ancient
sediments at Dikika are pebbles too small for making tools," says
McPherron. "The hominins at this site probably carried their stone
tools with them from better raw material sources elsewhere. One of our
goals is to go back and see if we can find these locations, and look
for evidence that at this early date they were actually making, not
just using, stone tools."

Regardless of whether or not Selam and her relatives were making their
own tools, the fact that they were using them to access nutritious
meat and marrow from large mammals would have had wide-ranging
implications for A. afarensis both physically and behaviorally.

"We now have a greater understanding of the selective forces that were
responsible for shaping the early phases of human history," says
Alemseged. "Once our ancestors started using stone tools to help them
scavenge from large carcasses, they opened themselves up to risky
competition with other carnivores, which would likely have required
them to engage in an unprecedented level of teamwork."

While many questions remain about the history of tool use, tool
making, and related dietary changes among human ancestors, this
discovery adds a rich new chapter to the story -- a story that is
deeply relevant to what makes us unique as a species.

This research was conducted under the auspices of the Ethiopian
Authority for Research and Conservation of Cultural Heritage /
Ministry of Culture and Tourism. Financial support for the 2009 field
and laboratory work was provided by the California Academy of
Sciences. Travel expenses for D.G., S.P.M., D.N.R. and J.G.W. were
covered by their respective institutions.



Letter

Nature 466, 857-860 (12 August 2010) | doi:10.1038/nature09248;
Received 9 April 2010; Accepted 1 June 2010


Evidence for stone-tool-assisted consumption of animal tissues before
3.39 million years ago at Dikika, Ethiopia

Shannon P. McPherron1, Zeresenay Alemseged2, Curtis W. Marean3,
Jonathan G. Wynn4, Denné Reed5, Denis Geraads6, René Bobe7 & Hamdallah
A. Béarat8

1. Department of Human Evolution, Max Planck Institute for
Evolutionary Anthropology, DeutscherPlatz 6, Leipzig 04103, Germany
2. Department of Anthropology, California Academy of Sciences, 55
Concourse Drive, San Francisco, California 94118, USA
3. Institute of Human Origins, School of Human Evolution and Social
Change, PO Box 872402, Arizona State University, Tempe, Arizona
85287-2402, USA
4. Department of Geology, University of South Florida, 4202 E
Fowler Ave, SCA 528, Tampa, Florida 33620, USA
5. University of Texas at Austin, Department of Anthropology, 1
University Station C3200, Austin, Texas 78712, USA
6. Centre National de la Recherche Scientifique, UPR 2147, 44 Rue
de l'Amiral Mouchez, Paris 75014, France
7. Department of Anthropology, University of Georgia, Athens,
Georgia 30602, USA
8. School for Engineering of Matter, Transport and Energy, Ira A.
Fulton Schools of Engineering, Arizona State University, Tempe,
Arizona 85287-6106, USA

Correspondence to: Shannon P. McPherron1 Email: mcpherron@xxxxxxxxxx

Top of page
Abstract

The oldest direct evidence of stone tool manufacture comes from Gona
(Ethiopia) and dates to between 2.6 and 2.5 million years (Myr) ago1.
At the nearby Bouri site several cut-marked bones also show stone tool
use approximately 2.5 Myr ago2. Here we report stone-tool-inflicted
marks on bones found during recent survey work in Dikika, Ethiopia, a
research area close to Gona and Bouri. On the basis of low-power
microscopic and environmental scanning electron microscope
observations, these bones show unambiguous stone-tool cut marks for
flesh removal and percussion marks for marrow access. The bones derive
from the Sidi Hakoma Member of the Hadar Formation. Established 40Ar–
39Ar dates on the tuffs that bracket this member constrain the finds
to between 3.42 and 3.24 Myr ago, and stratigraphic scaling between
these units and other geological evidence indicate that they are older
than 3.39 Myr ago. Our discovery extends by approximately 800,000
years the antiquity of stone tools and of stone-tool-assisted
consumption of ungulates by hominins; furthermore, this behaviour can
now be attributed to Australopithecus afarensis.

1. Department of Human Evolution, Max Planck Institute for
Evolutionary Anthropology, DeutscherPlatz 6, Leipzig 04103, Germany
2. Department of Anthropology, California Academy of Sciences, 55
Concourse Drive, San Francisco, California 94118, USA
3. Institute of Human Origins, School of Human Evolution and Social
Change, PO Box 872402, Arizona State University, Tempe, Arizona
85287-2402, USA
4. Department of Geology, University of South Florida, 4202 E
Fowler Ave, SCA 528, Tampa, Florida 33620, USA
5. University of Texas at Austin, Department of Anthropology, 1
University Station C3200, Austin, Texas 78712, USA
6. Centre National de la Recherche Scientifique, UPR 2147, 44 Rue
de l'Amiral Mouchez, Paris 75014, France
7. Department of Anthropology, University of Georgia, Athens,
Georgia 30602, USA
8. School for Engineering of Matter, Transport and Energy, Ira A.
Fulton Schools of Engineering, Arizona State University, Tempe,
Arizona 85287-6106, USA

http://www.nature.com/nature/journal/v466/n7308/full/nature09248.html
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