presentation

2. WHAT IS FORENSIC ANTHROPOLOGY?
Is the study of the identification,
analysis and interpretation of human
skeletal remains from forensic
contexts.
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3. Examination of human remains by forensic
anthropologists focuses on three tasks :
 Identifying the victim or at least
providing a biological profile ( age, sex,
stature, ancestry, anomalies, pathology
and individual features)
 Providing data regarding death event,
including evidence of trauma
 Reconstructing postmortem period
based on condition of the remains and
recovery context
Chapter 7
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4. ESTIMATING AGE
 Forensic physical anthropologist must be
familiar with size of skeletons at all ages
Timing of formation, growth and fusion of
diaphyses and epiphysis are patterned to
create estimate
Chapter 7
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6. DENTAL DEVELOPMENT
 Teeth can be a determinant of age or sex
 Tooth development differs by sex and population
Chapter 7
CRC Press: Forensic Science, James and
Nordby, 3rd Edition
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7. SEXUAL DIMORPHISM
 Male and female Homo Sapiens differ by size
 DNA methods can produce accurate determinate of
sex
 Genotype – genetic
 Phenotype- observed difference
 Determination of biological sex of skeletal remains
is an inexact science
Chapter 7
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8. FRICTION RIDGES
 People can be identified by their fingerprints.

9. FRICTION RIDGES
1. Friction ridges develop on the fetus in their
definitive form prior to birth.
2. Friction ridges are persistent throughout life
except for permanent scarring, disease or
decomposition after death.
3. Friction ridge paths and the details in small
areas of friction ridges are unique and never
repeated.
4. Overall friction ridge patterns vary within
limits which allow for classification.

12. GENE FACTS
Human genome = 3.4 billion base pairs
Number of human genes: approx 100,000
Genes vary in length: average 3,000 bp
 Only 5% of human genome is coding and
contains genes
Genes divided into exons and introns
Much of the function of the genome
unknown
 0.1% difference in DNA between individuals

13. The analysis of chromosomes is known as
karyotyping.
DNA fingerprinting, also known as DNA profiling,
is used in criminal and legal cases to
1. determine identity
2. determine parentage
3. Identify the origin of a blood, semen, or
saliva in a sample.

14. STEPS OF DNA FINGERPRINTING
 Extraction: DNA is extracted from cells or
tissues of the body.

15. DNA – FORENSIC ANALYSIS
Collection of Evidence:
Types of Unknown Samples: Blood,
Semen, Stains, Saliva, Hair follicles,
Tissue, Bones, Teeth
Types of Known Samples: Blood /
buccal swabs from suspect / victim /
other known person.
**Avoid Contamination of DNA Evidence

17.  Restriction Fragments: DNA is cut by restriction
enzymes. Restriction enzymes recognize a
unique pattern of DNA bases (restriction sites)
and will cut the DNA at that specific location.
Restriction fragments of varying lengths are formed
when the DNA is cut.
 Amplification: Specifically chosen DNA fragments
are amplified using polymerase chain reaction.

18.  Electrophoresis: DNA is loaded into the wells
found in an agarose gel. When an electric current is
passed through the gel, the negatively charged
DNA fragments (pieces of DNA) migrate toward the
positive end of the gel. DNA fragments are
separated by size, with the smallest DNA fragments
moving the fastest through the gel.

19. Transfer DNA to Nylon sheet by soaking
them overnight.
 Probing is done by adding radioactive or
colored probes to nylon sheet to produce a
pattern called DNA fingerprint.
DNA Fingerprint is built using several
probes (5-10) probes simultaneously.

21. DNA PROFILING USING STRS
• STRs are Short Tandem Repeats of patterns of nucleotides spread
throughout our DNA
• The number of repeats at a certain distinct region (locus, plural=loci)
of DNA is highly variable from person to person allowing their use in
human identity testing
• The number of nucleotides involved in the repeats can vary between
9 and 80 (called variable number of repeats, VNTRs, or
minisatellites) or between 2 and 5 (called microsatellites, SHORT
tandem repeats, STRs)
• Several loci along our DNA have been identified as possessing
STRs, and the DNA profiling community has selected 13 regions for
identity analysis
• These 13 loci ALL contain 4 nucleotide (tetrameric) repeats
AATG AATG AATG AATG AATG AATG AATG DNA molecule
7 short, tandem (back to back) repeats of the nucleotide sequence AATG

22. SHORT TANDEM REPEAT (STR)
It can start with a much smaller sample of DNA. STR analysis
examines how often base pairs repeat in specific loci, or locations, on a
DNA strand. These can be dinucleotide, trinucleotide, tetranucleotide or
pentanucleotide repeats -- that is, repetitions of two, three, four or five
base pairs.
The likelihood that any two individuals (except identical twins) will have
the same 13-loci DNA profile can be as high as 1 in 1 billion or greater.

23. EXAMPLE
http://evolution.berkeley.edu

24. Which of the following questions would not be
asked of a family member of a victim of a mass
disaster?
A What is the name of the victim's dentist?
B Did the victim have any birthmarks, scars or
tattoos?
C What was the victim's sexual orientation?
D All of the above

25. Which of the following should be done at any
outdoor forensic anthropological investigation?
A Avoid contamination
B Treat all findings as equally important
C Secure area