330 likes | 3.05k Views
Ancestry/Race determination using the human skeleton. Forensic Anthropology 11-7-2008. Objective. We will spend the next several weeks learning how to draw up a biological profile using human skeletal remains Ancestry Sex Stature Age Trauma and Identifying features. Methods of Analysis.
E N D
Ancestry/Race determination using the human skeleton Forensic Anthropology 11-7-2008
Objective • We will spend the next several weeks learning how to draw up a biological profile using human skeletal remains • Ancestry • Sex • Stature • Age • Trauma and Identifying features
Methods of Analysis • Anthropometry; ‘measurement of mankind’ • Osteometrics; measurements of skeleton • Craniometrics; measurements of skull • Anthroposcopy: visual differences
Craniometric measures • Defined set of points on the skull, allow for precise, reproducible measurements of the skull • Frankfort horizontal (anatomical position) – line up bottom margin of the orbit with the external auditory meatus
Craniometric points • Set of points for precise cranial measurements • Describe specific areas of the skull • Some are single points, some paired
Craniometric points • Used to measure height, breadth, thickness of… • E.g. max cranial length, max cranial breadth, bizygomatic breadth, max cranial height, cranial base length, upper facial height, nasal height/breadth, biorbital breadth, mastoid length, mid-orbital width, etc….
Bregma Glabella Nasion Nasospinale Gnathion Gonion Alare Orbitale Euryon Vertex Apex Pterion Lambda Mastoidale Basion Opisthion Inion opisthocranion Which to know…
Race/ancestry • Like sex, race is discrete and continuous • Sex 2 categories, race many • Sex biologically determined, race categories culturally determined (not genetic)
Race/ancestry • Usually analysis limited to adult remains • There is much overlap between categories • Remains that exhibit ambiguous grouping should be considered as minority group • E.g. Remains with equal white and black characteristics considered black
Race/ancestry • U.S. ethnic groups • White (Caucasian)* • Black (African/Negroid)* • Hispanics • Asian (Mongoloid)* • Native American • other
Anthropomorphic traits of ancestry • Can take some time to become familiar with these traits • Remember – discrete categories are subjective • E.g. projecting vs non-projecting • Remains may be ‘intermediate’
Ancestry traits (Table 7.2)http://webtest.austin.utexas.edu/eforensics/AncestryEstimationTop.cfm • Nose • Root (nasion) • Bridge (C) • Spine (D) • Nose • Lower border (sill) B • Width (opening) A A: Nasal openingB: Nasal sillC: Nasal boneD: Nasal spine http://www.nlm.nih.gov/visibleproofs/media/special/ii_a_103g_3_ancestry.jpg
Face Projection/profile Height/shape Shape of orbit Orbit lower border Vault Browridges Muscle markings Sutures postcoronal Ancestry traits
Jaws and teeth • Tooth size • Shape of dental arch/palate • Incisors • Gonial inversion
East Asian/Native American Zygomatic arch tubercle projection Orthognathic (flat) Nasal spine average projection Little or no overbite Teeth Wide palate Elliptical (rounded) tooth row Shovel-shaped incisors Straight palatine suture Ancestry and the skull p. 48 Burns
Northern European Narrow nasal aperature Sharp nasal margin Orthognathic Overbite Crowded dentition Teeth Narrow palate with jagged/arched suture Parabolic row Straight incisors Most common group missing 3rd molar Ancestry and the skull
Central to South African Wide nasal aperture w/ guttered margin Prognathic profile w/ projecting maxilla No nasal spine Teeth Moderate palate width w/ curved palatine suture Hyperbolic dental row/ U-shaped Straight incisors Ancestory and the skull
Ancestry and the femur • Anterior curvature varies with populations • African populations generally have straighter femora • European, Asian populations have greater curvature • Metrically: AP/ML width of femur distal to Lesser trochanter
Craniometrics and ancestry • Direct measurements • Distal femur: angle of intercondylar shelf • Need xrays • Indexes • Height divided by width • Maxillofrontal, zygoorbital, alpha