M2: The Biological Profile
Lecture 9
Estimating Sex
PART 1 – SEX SPECIFIC ASPECTS OF PELVIC
ANATOMY
(1) The basic elements of an initial forensic examination
should…
o Identify basic demographic information about decedent (person
ELEMENTS OF A who died)
FORENSIC o Screen for features leading to a positive identification (an exact
person identified)
INVESTIGATION (2) Reconstruct cause of death, manner of death, help interpret
crime scene
o UNIT 3
SEXING
o Discriminating between “male” and “female”
o There are metric and non-metric ways of determining sex
o Involves sexual dimorphism
DETERMINING AGING
o Estimation of an individual’s age at death
AGE, SEX,
① Absolute Age
ANCESTRY, AND ② Age Class
STATURE FROM ③ Seriation – relative age; place in order: youngest to oldest
SKELETAL ANCESTRY
o Estimation of an individual’s heritage
REMAINS
ESTIMATING STATURE
o Determining height of an individual
o Based on creating a relationship of some measurable features to
that on an individual of known height: REGRESSION ANALYSIS
FORENSIC (1) Identify his or her sex
o Eliminates 50% of the population of missing persons from
INVESTIGATION consideration for a John Doe/Jane Doe
PHASE 1: o Since women give birth structure of pelvis reflects this
BASIC o Also based in the fact that men are larger than women
INFORMATION based on evolutionary history of monogamy
Determining biological sex
Male, Female, Or Indeterminate
“SEXING” A Based on degree of sexual dimorphism in a population
SKELETON Note that sex ≠gender
o Sex = Biological Term
, M2: The Biological Profile
o Gender = Social Term
METRIC
o Dimensions with breakpoints
o Ex.) max diameter of humeral or femoral head
METHODS NONMETRIC
o Pelvic Morphology
o Cranial Morphology
SEXUAL DIMORPHISM
o “Sex-Based Two Forms”
o The tendency for males and females of a species to vary in size,
with males being larger in primates
o In most primates males will be larger than females
SEXUAL
DIMORPHISM
Order of Accuracy
ASSESSING SEX o Pelvis – primary sexual characteristics
FROM THE o Cranium – secondary sexual characteristics
SKELETON o Postcranium and Dentition – based on sexual dimorphism
Sex characteristics of the skeleton are not well developed until
adolescence and beyond
ADULTS ONLY Although some methods of sexing subadults have been advanced, none
has been tested adequately and accepted
Pelvis differences reflect primary sexual characteristics
PARTURITION
Can be 95% Accurate
PELVIC
MORPHOLOGY SUB-PUBIC ANGLE
Females have a wider sub-pubic angle than males
Lecture 9
Estimating Sex
PART 1 – SEX SPECIFIC ASPECTS OF PELVIC
ANATOMY
(1) The basic elements of an initial forensic examination
should…
o Identify basic demographic information about decedent (person
ELEMENTS OF A who died)
FORENSIC o Screen for features leading to a positive identification (an exact
person identified)
INVESTIGATION (2) Reconstruct cause of death, manner of death, help interpret
crime scene
o UNIT 3
SEXING
o Discriminating between “male” and “female”
o There are metric and non-metric ways of determining sex
o Involves sexual dimorphism
DETERMINING AGING
o Estimation of an individual’s age at death
AGE, SEX,
① Absolute Age
ANCESTRY, AND ② Age Class
STATURE FROM ③ Seriation – relative age; place in order: youngest to oldest
SKELETAL ANCESTRY
o Estimation of an individual’s heritage
REMAINS
ESTIMATING STATURE
o Determining height of an individual
o Based on creating a relationship of some measurable features to
that on an individual of known height: REGRESSION ANALYSIS
FORENSIC (1) Identify his or her sex
o Eliminates 50% of the population of missing persons from
INVESTIGATION consideration for a John Doe/Jane Doe
PHASE 1: o Since women give birth structure of pelvis reflects this
BASIC o Also based in the fact that men are larger than women
INFORMATION based on evolutionary history of monogamy
Determining biological sex
Male, Female, Or Indeterminate
“SEXING” A Based on degree of sexual dimorphism in a population
SKELETON Note that sex ≠gender
o Sex = Biological Term
, M2: The Biological Profile
o Gender = Social Term
METRIC
o Dimensions with breakpoints
o Ex.) max diameter of humeral or femoral head
METHODS NONMETRIC
o Pelvic Morphology
o Cranial Morphology
SEXUAL DIMORPHISM
o “Sex-Based Two Forms”
o The tendency for males and females of a species to vary in size,
with males being larger in primates
o In most primates males will be larger than females
SEXUAL
DIMORPHISM
Order of Accuracy
ASSESSING SEX o Pelvis – primary sexual characteristics
FROM THE o Cranium – secondary sexual characteristics
SKELETON o Postcranium and Dentition – based on sexual dimorphism
Sex characteristics of the skeleton are not well developed until
adolescence and beyond
ADULTS ONLY Although some methods of sexing subadults have been advanced, none
has been tested adequately and accepted
Pelvis differences reflect primary sexual characteristics
PARTURITION
Can be 95% Accurate
PELVIC
MORPHOLOGY SUB-PUBIC ANGLE
Females have a wider sub-pubic angle than males
