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Chapter 12
Bioarchaeological
Approaches to the Past
Outline
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Skeletal Analysis: The Basics
How Well Did the Stillwater People Live?
Reconstructing Diet from Human Bone
Lives of Affluence? Or Nasty, Brutish, and
Short?
• Archaeology and DNA: Tracing Human
Migrations
Bioarchaeology
• The study of the human biological component
of the archaeological record by exploring
bone, bone chemistry, and DNA preserved in
human tissues to:
– Learn the origin and distribution of disease
– Reconstruct human diets
– Analyze evidence for biological stress in
archaeological populations
Skeletal Analysis:
The Basics
• We use characteristics of several
bones, notably the pelvis and skull, to
determine an individual’s sex.
• An individual’s age can be determined
by tooth eruption.
• Patterns of bone fusion, tooth wear, and
bone wear are used to age individuals
over the age of 25.
Some Major Bones of the
Human Skeleton
The Stillwater People
• The Stillwater burials derived from a 16square kilometer area of marsh.
• Few of the burials contained grave
goods.
• Bioarchaelogist, Larson derived how
many men, women, infants, and
adolescents there were, and their
approximate ages.
Paleopathology and the
Stillwater people
• Larsen turned to paleopathology, the
study of ancient disease, to learn more
about the Stillwater people.
• Larsen looked for nonspecific indicators
of stress caused by nutritional
deficiency and infectious diseases.
Environmental factors and
Imprints on Human Bone
Disease and Trauma at
Stillwater
• Larson found signs of iron deficiency anemia
among the skeletal remains from Stillwater
Marsh.
• Every single adult skeleton in the Stillwater
collection had osteoarthritis in at least one
joint.
• The femur cross sections and patterns in
osteoarthritis indicated that the people living
at Stillwater Marsh walked a great deal to
make a successful living.
Paleodemography
• Paleodemography reconstructs parameters
such as life expectancy at birth, the age
profile of a population, and patterns in the
ages of death.
• Bioarchaeologists do this by constructing
various sorts of mortality profiles for a
prehistoric population based on the age and
sex data of burials.
• Mortality profiles show at what age adult
males, adult females, and children died.
The Stillwater Mortality
Profile
The Stillwater Mortality
Profile
• Mortality of newborns and toddlers is very
high among hunting and gathering
populations.
• The female mortality profile shows an
increase in deaths in the early child-bearing
years; common for foraging populations.
• Few individuals are assigned to the 46–50
and 50+ age categories. A 47-year-old in
Stillwater was an elder.
Reconstructing Diet from
Human Bone
• Diet can be reconstructed from human bone
in several ways.
• Cavities indicate a starchy diet.
– Because their diet was low in simple
carbohydrates, only 3% of Stillwater
skeletons had cavities.
• Ancient diets can also be reconstructed by
analyzing the carbon and nitrogen stable
isotopes preserved in human bone.
Bone and Stable Isotopes
• Human bones reflect the isotopic ratios of
plants ingested during life.
• We reconstruct the dietary importance of
plants by measuring the ratio of carbon
isotopes in bone collagen.
– A diet rich in C4 plants (maize), can
produce bones with a higher ratio of 13C to
12C.
– Humans who consume large amounts of
meat have a higher ratio of 15N to 14N.
Comparison of Carbon and Nitrogen
Isotopes
Molecular Archaeology
• Uses genetic material— DNA from
human skeletal remains and living
peoples— so geneticists and
archaeologists can join forces to create
a new approach to reconstructing the
past.
Background on DNA
• nuclear DNA - Genetic material found in a
cell’s nuclei; responsible for inherited traits.
• Gene - A unit of the chromosomes that
controls inheritance of particular traits.
• mitochondrial DNA (mtDNA) - Genetic
material found in the mitochondria of cells;
inherited only from the mother, mutates at a
rate of 2–4% per 1 million years.
Prospecting for Ancient DNA
• In 1984, Allan Wilson and his student Vince
Sarich were the first to identify genetic
materials from old tissue.
• The next year, Swedish researcher Svante
Pääbo cloned DNA from a 4400-year-old
Egyptian mummy.
– This was the first time that anyone had
applied PCR techniques to ancient
humans.
Prospecting for Ancient
DNA
• Wilson and his team continued to collect
mtDNA samples from around the world and
compared the human data with that of
chimpanzees.
• All living human groups share all but about
0.6% mtDNA.
– The 0.6% suggests a way to determine the
relatedness among living individuals and
groups.
An African Eve
• The investigators suggested that all the
genetic composition evident in living human
populations could be traced to a single
African ancestor.
• Because mtDNA is passed down strictly
through the maternal line, this ancestor must
have been female.
• She was quickly nicknamed Eve, after the
biblical first woman and wife of Adam.
Molecular Clock
• Calculations of the time since
divergence of two related populations
using the presumed rate of mutation in
mtDNA and the genetic differences
between the two populations.
Molecular Archaeology
• Uses data from living and ancient peoples to
reconstruct population migrations.
• Especially useful is mtDNA and the genetic
material in Y chromosomes.
• Although we have much to learn about the
rates at which DNA mutates, current studies
suggest DNA research will someday be
important to reconstructing the past.
Quick Quiz
1. Bioarchaeology is used in the following
types of research:
A. Learning the origin and distribution of
disease.
B. Reconstructing human diets.
C. Analyzing evidence for biological stress
in archaeological populations
D. All of the above.
Answer: D
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Bioarchaeology is used to learn the
origin and distribution of disease,
reconstruct human diets and analyze
evidence for biological stress in
archaeological populations.
2. Characteristics of the the pelvis and
skull can help to determine an
individual’s ____, while ____ can be
determined by tooth eruption.
Answer: sex, age
• Characteristics of the the pelvis and
skull can help to determine an
individual’s sex while age can be
determined by tooth eruption.
3. Paleodemography reconstructs parameters
such as:
A. life expectancy at birth
B. age profile of a population
C. population migrations
D. A and B only.
E. A, B and C.
Answer: D
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Paleodemography reconstructs parameters
such as life expectancy at birth and the
age profile of a population.
4. The _____ ______ calculates the time
since divergence of two related
populations using the presumed rate of
mutation in mtDNA and the genetic
differences between the two
populations.
Answer: molecular clock
• The Molecular Clock calculates the
time since divergence of two related
populations using the presumed rate of
mutation in mtDNA and the genetic
differences between the two
populations.