• Once archaeologists have found a site and recovered
artifacts and other materials from it, they are ready to
begin “reading” what they have found to learn the story of
the past.
• The reading of the archaeologists is called analysis.
• Much of what is lost and discarded by humans never
survive. Much of what does survive comes to us in
fragments and in a fragile, deteriorated state.
• Before doing analysis, then, archaeologists and
paleoanthropologists must first conserve and reconstruct
the materials they have found.
• Conservation is the process of treating artifacts to stop
decay and if possible, reverse the deterioration process.
• Some conservation is very simple, involving only cleaning
and drying the item.
• Some conservation is highly complex, involving longterm chemical treatment and long-term storage under
controlled conditions.
• The 5,000 year-old “Ice Man” found in 1993 has to be kept
permanently in glacial-like conditions.
• Reconstruction is like building a three-dimensional
puzzle where you’re not sure which pieces belong and you
know not all of the pieces are there.
• First, archaeologists typically examine the form or shape of an
artifact.
• For most common artifacts, such as ceramics, forms are known well
enough to be grouped into a typology or set of types, which is the
primary purpose of formal analysis.
• Typology provide a lot of information about the artifact,
including:
• Its age
• Species and culture where it comes from.
• Sometimes, how it was made, used, or exchanges.
• Reconstruction is like building a three-dimensional
puzzle where you’re not sure which pieces belong and you
know not all of the pieces are there.
• Second, archaeologists often measure artifacts, recording their
size in various, often strictly defined, dimensions. This is called
metric analysis.
• Third, archaeologists, often attempt to understand how an
artifact was made.
• By examining the materials the artifact is made from and how that
material was manipulated, archaeologists can learn about the
technology, economy, and exchange system of the people who made
the artifact.
• Reconstruction is like building a three-dimensional
puzzle where you’re not sure which pieces belong and you
know not all of the pieces are there.
• Finally, archaeologists attempt to understand how an artifact
was used.
• Knowing how an artifact was used gives the archaeologist a direct
window onto ancient life.
• For stone, bone and wood tools, there is a technique called usewear analysis which can determine how a tool was used through
the careful examination of the kind of wear on its edges.
• Knowing how an artifact was made allows the archaeologists to
understand the technology and technical abilities of people in
the past. For example: Thomas Wynn analyzed both the final
forms and the methods used by early humans – Homo erectus
– to make stone tools roughly 300,000 years ago. He found
that manufacturing these tools was a multistage process,
involving several distinct steps and several distinct stoneworking techniques to arrive at the finished product. He then
took his information and evaluated it in term of measure of
human cognitive ability developed by Jean Piaget, and
concluded that the people who made these tools probably had
organizational abilities similar to those of modern humans.
• Knowing how an artifact was used allows the
archaeologists to know something of people’s behavior
and activities. Lawrence Keeley conducted detailed usewear analyses on Acheulian hand axes made by Homo
erectus peoples and found that they had a variety of uses.
•
•
•
•
Some cut meat.
Others for wood
To dig in the group (probably for edible roots).
Therefore hand axes appear to have been multipurpose tools
for our Homo erectus ancestors – something like a Swiss Army
knife.
• Ecofacts are diverse, and what archaeologists and
paleoanthropologists can learn from them is highly
diverse as well.
• Paleontologists (studying humans or other species) can
tell a great deal about an extinct animal from its fossilized
bones or teeth, but that knowledge is based on much
more than just the fossil record itself.
• Paleontologists rely on comparative anatomy to help
reconstruct missing skeletal pieces
• New techniques, such as electron microscopy, CAT scans
and computer provide much information about how the
organism may have moved about.
• Chemical analysis of fossilized can suggest what the
animal typically ate.
• Paleontologists are also interested in the surroundings of
the fossil finds
• Much of the evidence for primate evolution comes from
teeth, which are the most common animal parts (along
with jaws) to be preserved as fossils.
• Animals vary in dentition – the number and kinds of
teeth they have, their size, and their arrangement in the
mouth.
• Dentition provides clues to evolutionary relationships
because animals with similar evolutionary histories often
have similar teeth.
• For example, no primates, living or extinct, has more than two
incisors in each quarter of the jaw. That feature, along with
others, distinguishes the primates from earlier mammals,
which had three incisors in each quarter.
• Dentition also suggests the relative size of an animal and
often offer clues about its diet.
• For example, comparison of living primates suggested that fruit
eaters have flattened, rounded tooth cusps, unlike leaf- and
insect- eaters, which have more pointed cusps.
• Paleontologists can tell much about an animal’s posture
and locomotion from fragments of its skeleton.
• Arboreal quadrupeds have front and back limbs of about the
same length; because their limbs tend to be short, their center
of gravity is close to the branches on which they move. They
also tend to have long grasping fingers and toes.
• Paleontologists can tell much about an animal’s posture
and locomotion from fragments of its skeleton.
• Terrestrial quadrupeds are more adapted for speed so they
have longer limbs and shorter fingers and toes.
Disproportionate limbs are more characteristics of vertical
clingers and leapers and brachiators (species that swing
through the branches).
• Vertical clingers and leapers have longer, more powerful
hind limbs, branchiators have longer forelimbs.
• Because we cannot remove features to the lab, we cannot
subject them to the same range of analyses as artifacts,
ecofacts, and fossils.
• Archaeologists developed a number of powerful tools to
analyze features in the field.
• The primary one is detailed mapping, usually using a surveyor’s
transit.
• Geographic information system (GIS) allow the archaeologist
to produce a map of the features on a site and combine that
map with information about other archaeological materials
found there.
• Archaeologists do not study fossils and artifacts as
individual objects.
• They put all the materials discovered in one site in
context. This means how and why are the artifacts and
other materials are related – This is what archaeology is
all about.
• Fossils and artifacts maybe beautiful or interesting by
themselves, but it is only when
they are placed in context with
the other materials found on a
site that we are able to “read”
and tell the story of the past.
• An important part of putting artifacts and other materials
into context is putting them in chronological order
• Dating methods include:
• Relative dating is used to determine the age of a specimen.
• Absolute dating or chronometric dating is used to measure how
old a specimen or deposit is in years.
• Stratigraphy
• The study of how different rock and solid formations are laid
down in successive layers or strata.
• Oldest layers are generally deeper or lower than more recent
layers.
• The earliest, and still the most common used.
• Indicator artifacts or ecofacts are used to establish a
Stratigraphy sequence.
• If a site has been disturbed, Stratigraphy will not be a
satisfactory way to determine relative age.
• Many of the absolute dating methods are based on the decay of
a radioactive isotope. Because the rate of decay is known, the
age of the specimen can be estimated, within a range of
possible error.
• Radiocarbon Dating or Carbon 14 dating
• The most popular known methods of determining the absolute age
of a specimen.
• All living matter possesses a certain amount of radioactive form of
carbon (Carbon 14). After an organism
dies, it no longer takes in any of the
radioactive carbon. Carbon-14 decays
at a slow but steady pace and reverts
to nitrogen-14. The rate at which carbon
decays –its half life – is known: C-14
has a half life of 5,730 years
• Thermoluminescence Dating
• Many minerals emit light when they are heated.
• This cold light comes from the release, under heat, of “outside”
electrons trapped in the crystal structure.
• Thermoluminescence dating makes use of the principle that if an
object is heated at some point to a high temperature it will release
all the trapped electrons it held previously. The amount of
Thermoluminescence emitted when the object is tested during
testing allows researchers to calculate the age of the object.
• Thermoluminescence dating is well suited to sample of ancient
pottery, brick, tile, and other objects that are made at high
temperatures.
• Electron Spin Resonance Dating
• Measures trapped electrons then expose them to magnetic
fields.
• Paleomagnetic Dating
• When rock of any kind form, it records the ancient magnetic
field of the earth. Since the earth’s magnetic field has reversed
itself many times, the geomagnetic patterns in rocks can be
used to date the fossils within the rocks.
• Potassium-Argon Dating
• Potassium-40 decays at an established rate and forms argon40. The half-life of K-40 is a known quantity, so the age of a
material containing potassium can be measured by the amount
of K-40 c0mpared with the amount of Ar-40. Potassium-Argon
Dating us used to date samples from 5,000 years up t0 3 billion
years old
• Uranium-Series Dating
• The decay of two kinds of uranium U-235 and U-238 into other
isotopes.
• Used especially in caves where stalagmites and other calcite
formations form, because water usually contains uranium but
not thorium.
• Fission-Track Dating
• It entails counting the number of paths or tracks etched in the
sample by the fission-explosive division- of uranium atoms as
they disintegrate.
• One goal is the description or reconstruction of what happened in the
past.
• Archaeologists attempt to determine how people lived in a
particular place at a particular time, and when and how their
lifestyle changed
• Another goal is testing specific explanations about human evolution
and behavior.
• Understand general trends and patterns in human biological and
cultural evolution.
• Archaeology does not simply describe past cultures. It
can also have a profound effect on living people.
• For example, many people find the idea of archaeologists
excavating, cleaning, and preserving the remains of ancestors
to be offensive. Therefore, archaeologists must be sensitive to
the desires and beliefs of the populations that descend from the
ones they are researching.
• Artifacts from some ancient cultures are in great demand by art and
antiquities collectors, and archaeological digs can lead to
uncontrolled looting if archaeologists are not careful about how and
to whom they report their discoveries.
• Archeologists must report all their findings to the public. Since by
excavating a site, they damage it, they must document everything for
future archaeologists who are excavating the same site.