2. Sex Estimation

Question 1

What 3 things is sex estimation influenced by?

Answer 1

• Age
• Population affiliations
• Preservation and Completeness of skeletal remains

Question 2

What are the accuracy’s for sex estimation from:

• Whole skeleton
• Pelvis
• Skull
• Long Bones

Answer 2

• Whole skeleton - 90-95%
• Pelvis - 90%
• Skull - 80%
• Long Bones - 70%

Question 3

What 2 tests are used to assess accuracy and bias in sex estimation?

Answer 3

• Direct tests - effectiveness in classifying known-sex individuals
• Indirect tests - calculated sex ratio in representative sample of skeletons

Question 4

What are most diagnostic traits of sex related to?

Answer 4

Childbirth or muscle attachments

Question 5

What are the sex differences in cranium:

• Glabella
• Supraorbital ridge
• Mastoid process
• External occipital protuberance
• Nuchal area
• Gonial angle
• Orbital margins
• Lower first molar

Answer 5

• Glabella is more angular and prominent in males
• Supraorbital ridge more prominent in males
• Mastoid process larger in males
• External occipital protuberance larger in males
• Nuchal area more ridged in males
• Gonial angle protrudes more laterally in males
• Orbital margins sharp in females but rounded in males
• Lower first molar has 4 cusps in females but 5 cusps in males

Question 6

What are the sex differences in pelvis:

• Overall shape
• Obturator foramen
• Acetabulum
• Sub-pubic angle
• Ventral arcs
• Sacrum
• Pubis
• Pelvis inlet

Answer 6

• Pelvis is shallower, broader and more rectangular in females
• Obturator foramen are triangular in females but oval in males
• Acetabulum are smaller and face anterolaterally in females
• Sub-pubic angle is U-shaped in females but V-shaped in males
• Ventral arcs are present in females
• Sacrum is broader in females
• Medial-pubis extension in females
• Pelvic inlet is oval-shaped in females but heart-shaped in males

Question 7

What measurements are discriminant function analysis of the pelvis based on?

Answer 7

• Ischial length
• Acetabulum diameter
• Pubis Length

Question 8

What is the estimated sex if the discriminant function analysis is:

• Negative
• Positive

Answer 8

• Negative = female

- Positive = male

Question 9

What are 2 potential indicators of pregnancy and partuition in skeletal remains?

Answer 9

• Discrete zones of cortical resorption (pits) particularly on posterior margin of pubic symphysis
• Extended pubic tubercle (attachment for inguinal ligament and rectus abdominius)

Question 10

Apart from skull and pelvis, what does sex discrimination rely on?

Answer 10

Average size differences between the sexes, particularly in sizes of articulating surfaces at ends of long bones

Question 11

What are the most useful long bones for sex estimations?

Answer 11

Humerus, Radius and Femur

Question 12

What are metric dimensions heavily influenced by?

Answer 12

Population affinities

Question 13

When do reliable skeletal sex differences emerge at?

What does this make difficult?

Answer 13

• Puberty

- Sexing immature skeletal remains

Question 14

What 5 sex diagnostic traits have authors identified in children

Answer 14

• Mandibular symphysis
• Gonial angle
• Greater sciatic notch
• Iliac crest curvature
• Orbital margins

Question 15

What 2 bio-molecular methods can be used in sex estimation?

Answer 15

• Amplification of amelogenin genes

- Amplification of Y-repeat sequences

Question 16

What are amelogenin genes?

What is the issue with using them in sex estimation?

Answer 16

• Short lengths of DNA (112bp) that are amplified, with short (6bp) differences between X and Y chromosomes
• Only present as single copies per chromosome, therefore allelic drop-out can result in an XY individual identified as an X individual

Question 17

What are Y-repeat sequences?

What does their presence/absence suggest?

Answer 17

• Short sequences present in multiple copies on Y chromosome
• Presence indicates male, absence may indicate failure of method