112 CHAPTER 5 | Field Methods in Archaeology and Paleoanthropology
structure. The relationships among populations can also be
traced through material remains (Figure 5.4).
Dental specimens are frequently analyzed under the
microscope to examine markings on teeth that might pro-
vide clues about diet in the past. Specimens are now regu-
larly scanned using computed tomography (CT) to analyze
structural details of the bone. Imprints or endocasts of the
insides of skulls are taken to determine the size and shape
of ancient brains.
Advances in genetic technology are now applied to
ancient human remains. Anthropologists extract genetic
material from skeletal remains in order to perform DNA
comparisons among the specimen, other fossils, and liv-
ing people. Small fragments of DNA are amplified or cop-
ied repeatedly using polymerase chain reaction (PCR)aid looting through sharing site and artifact location
information on the Internet, which has also provided a
market for artifacts.
Once the artifact or fossil has been freed from the sur-
rounding matrix, a variety of other laboratory methods
come into play. Generally, archaeologists and paleoanthro-
pologists plan on at least three hours of laboratory work for
each hour of fieldwork. In the lab, artifacts that have been
recovered must first be cleaned and catalogued—often a
tedious and time-consuming job—before they are ready
for analysis. From the shapes of the artifacts as well as from
the traces of manufacture and wear, archaeologists can
usually determine their function. For example, the Russian
archaeologist S. A. Semenov devoted many years to the
study of prehistoric technology. In the case of a flint tool
used as a scraper, he was able to determine, by examining
the wear patterns of the tool under a microscope, that the
prehistoric individuals who used it began to scrape from
right to left and then scraped from left to right, and in so
doing avoided straining the muscles of the hand.^4 From
the work of Semenov and others, we now know that right-
handed individuals made most stone tools preserved in the
archaeological record, a fact that has implications for brain
S-twist ( \ ) Z-twist ( / )Figure 5.4 In northern New England, prehistoric pottery was
often decorated by impressing the damp clay with a cord-
wrapped stick. Examination of cord impressions reveals that
coastal people twisted fibers used to make cordage to the left
(Z-twist), while those living inland did the opposite (S-twist).
The nonfunctional differences reflect motor habits so deeply
ingrained as to seem completely natural to the cordage makers.
From this, we may infer two distinctively different populations.endocast A cast of the inside of a skull; used to help deter-
mine the size and shape of the brain.
polymerase chain reaction (PCR) A technique for ampli-
fying or creating multiple copies of fragments of DNA so that it
can be studied in the laboratory.(^4) Semenov, S. A. (1964). Prehistoric technology. New York: Barnes & Noble.
In September 2006, researchers
announced the discovery of a spectacular
new fossil—the skeleton of a young child
dated to 3.3 million years ago. The fossil
was actually discovered in the Dikika area
of northern Ethiopia in 2000. Since then,
researchers worked on careful recovery
and analysis of the fossilized remains
so that when the announcement was
made, a great deal was already known
about the specimen. Their analyses have
determined that this child, a little girl
about 3 years old who likely died in a
flash flood, was a member of Australo-
pithecus afarensis, the same species as
the famous Lucy specimen (see Chapter 7).
Due to the importance of this find, some
scientists have referred to this child as
“Lucy’s baby” though the child lived about
150,000 years before Lucy.
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