ancestry pt II
Card Set Information
ancestry pt II
related to ancestry - very difficult to identify
asian classified under?
areas of skull most diagnostic for acestry, which areas most important
Nose - importance?
most useful for determining ancestry
root= where nasal bone meets frontal bone
bridge- ridge of bone formed by nasal bone
spine- bone projecting from floor of nasal aperature
shape of lower border?
hole part as the bottom of the base of the nose
W - nasal root high, wide distance between lower orbit and nasal root, pronounced spine
A - nasal root low, narrow distance ""
B- nasal root low, narrow ""
W - nasal root narrow, isosceles triangle
A -nasal root intermiediate, opening intermiediate
B - nasal root wide, opening equilateral triable
bottom of nose
W - distinct "sill" on ower border of nose
B - indistinct lower border with "guttering"
A - intermiediate between two
Face - what is the diagnostic feature?
differences in facial projection due to diferent jaw sizes
facial projection entails?
tip of nasal bone to the forward projection of upper jaw
B- face projects forward
width of face (cheekbones)
W- Face narrow
A - Face wide
B - Face narrow
W- aglular eye orbits
A- rectangular eye orbits
B - round eye orbits
lower border of eye
A - lower boder of eye projects forward
B/W - lower border of eye relatively vertical
Shape of brain case - Vault
brow ridges and muscle attachments
W- more pronounced
W or B-basic not too complicated
A- more wavy and complex (interdigitation)
Wormian bones more common in
Post bregmatic depression (dip on top of skull)
B - dip seen in black people
W/A - flat - slightly convex
* unless individuals have their skulls have been artificially deformed. (first nations) not natural
Teeth and Jaws
W - teeth in white skulls have teeth too large for jaws
--> causes dental crowding
W - parabolic
B- hyperbolic (u-shaped)
W/B - spatulate
A - shovel shaped (90% in asian, and native american invdl.)
Post cranial traits
White and asian?
W/A = femora with anterior curvature
B = straight femoral shafts
femorial torsion (on the head of the femur)
very little femoral torsion in black people (head angles horizontally)
high degree of femoral torsion in white and asian individuals (head angled vertically)
Problems with metric methods for ancestry assesment?
populations have changed since early 20th century
methods of measurement unclear
--> measuring qualitative measurements as well (not independant)
post cranial measurement
Femur (direct measurement)
Can only be seen on an x-ray
femur 0 angle of intercondylar shelf of distal femus as seen on x-ray
White >141 degrees <black
metric measurements for ancestry determination
3 main ones in skull?
consists of two measurement (one divided by another x 100)
white - pointed chin
black - blunt chin
aisan - rounded chin and vertical acending ramus
preserves well in forensic context.
W - straight/ slightly wave, dense on scalp
B - naturally curelled grows more slowly,more parallel to scalp
A - grows the fastest, coarse, and perpendicular to skulls.
Is skin colour useful?
no, not in forensic context
dark skin will bleach white if lying on damp ground
after death,light skin begins to darken.