YEAR 10 EVOLUTION
HOMINID SKULL COMPARISON
Introduction
You are an Anthropologist in a team (ie 2 or 3) who are investigating the evolutionary relationships among
living and extinct human relatives.
Materials per team:
1 skull cast of each of the following:
1. Homo sapiens (modern human)
2. Pan troglodytes (modern chimpanzee) or Gorilla gorilla (modern gorilla)
3. Two of :
Homo neanderthalensis (Neanderthal), Homo erectus (Peking Man), Homo floresiensis (Hobbit),
Homo habilis (Handy Man), Australopithecus boisei (Nutcracker Man) Australopithecus afarensis
(Lucy) and Australopithecus africanis (Taung Child), Homo rudolphensis, Homo heidelbergensis.
Materials per team: 1 metric ruler
1 protractor
1 caliper
Photographs, and other visuals of humans, chimpanzees, and gorillas
Procedure: PART A – Comparison of Modern Apes and Humans
Using skull casts, photographs, and other visuals of humans, chimpanzees, and gorillas, your teacher will
engage you in a discussion during which you compare these modern hominids. During this discussion, you
should make a list of the features these hominids share and those features that make them differ. Use “Chart 1 A Comparison of Modern Apes and Humans” to record your observations.
Procedure: PART B – Comparing Modern and Extinct Hominid Skulls
In this part of the activity you will make detailed observations and measurements of skull casts of one modern
and two extinct hominids. You will then use your data to determine if the extinct hominids are more ape-like or
more human-like in appearance. Your data will also provide a basis for drawing some conclusions about
patterns of hominid evolution.
1. Your team will examine the skull casts chosen. For each skull you will need a metric ruler, protractor, and
caliper. A few “rules” should be followed:
 Do not make pencil or pen marks on the skulls.
 Be careful with the skulls. They are expensive reproductions that are breakable.
 Be sure to take turns in making the measurements.
 Measure in millimeters (mm). Round off to whole numbers.
2. Complete the “Chart 2 - Hominid Skull Comparison Data Table” as you examine your chosen skulls. Refer
to the “Hominid Skull Comparison Checklist” for a description of each hominid characteristic you observe.
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YEAR 10 EVOLUTION
Analysis
Using observations and measurements from your completed Chart 2- Hominid Skull Comparison Data Table,
answer the following question.
Question 1.
Which traits distinguish modern humans from other modern apes?
Question 2.
Are your chosen extinct hominids more closely related to modern humans or other modern apes such as
gorillas?
Question 3.
Briefly describe how the following characteristics have changed in hominid evolution from ape-like ancestors to
modern humans.
a. Size of cranium/brain.
b. Size of brow ridge.
c. Presence of sagittal crest.
d. Facial prognathism (protrusion of snout).
e. Size of chin.
f. Facial slope.
g. Size of canines.
h. Dental arcade.
i. Position of foramen magnum.
j. Forehead shape.
Question 4.
Suggest reasons for the changes you described in Question 3.
Only give answers to the following (a, b, g, i, j).
Question 5.
In terms of natural selection, describe how modern humans evolved a large brain from ape-like ancestors that
had a smaller brain.
Question 6.
Draw a phylogenetic tree that shows the position of the various hominids studied in this practical activity.
(Carry out an Internet Search)
Question 7.
Are modern apes ancestors to modern humans?
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YEAR 10 EVOLUTION
Chart 1 – A COMPARISON OF MODERN APES AND HUMANS
Structure
Description in Modern Humans
Description in Modern Apes
Eyes
Hands and feet
Arms and legs
Spine
Skull/cranium/brain/face
Teeth
Pelvic region
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YEAR 10 EVOLUTION
HOMINID SKULL COMPARISON CHECKLIST
1. FOREHEAD: Does the forehead (frontal bone) look more vertical or does it slope backward?
2. CHIN: Does the chin stick out or does it recede back?
3. SAGITTAL CREST: A sagittal crest is a bony ridge that runs from front to rear on top of the cranium. Is it small, medium, large,
or absent?
4. FACIAL PROGNATHISM: How much does the snout protrude when looking at the skull from the side? Is the protrusion large,
medium, small or absent?
5. BROWRIDGE: The brow ridge is a heavy mass of bone directly over the eye orbits. Rate it large, small, medium.
6. DENTAL ARCADE: This refers to the shape of the arrangement of the teeth in the jaw when looking directly at the chewing
surface of the teeth. Does the arrangement form a parabolic (rounded) shape with a relatively continuous outward curvature or is the
arrangement rectangular with the premolars and molars in parallel rows?
a = incisors
b = canines
c = premolars
d = molars
Parallel Arcade
Parabolic Arcade
7. CANINE TOOTH: What is the length in millimeters of the exposed part of the upper canine tooth?
8. DENTAL FORMULA: Record the number of incisors, canines, premolars and molars present in the upper jaw. (ICPM)
9. CANINE DIASTEMA: Is there a gap present on the upper jaw between the canines and incisors?
10. FORAMEN MAGNUM: The foramen magnum is a large opening in the back or bottom of the skull through which the spinal
cord enters the cranium. Determine if it is more to the rear or towards the bottom of the skull.
11. WIDTH OF CRANIUM: Use the caliper and ruler to determine the maximum width of the brain case. Measure from temple-totemple and record your answer in millimeters.
12. LENGTH OF CRANIUM: Use the caliper and ruler to determine the maximum length of the brain case. Measure from the
forehead to the back of the skull.
13. FACIAL SLOPE: Use the protractor to measure the angle make by the face and the upper jaw when viewed from the side.
Angle of facial slope
Length of cranium
Width of cranium
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YEAR 10 EVOLUTION
CHART 2 - HOMINID SKULL COMPARISON DATA TABLE
FEATURES
A
Modern
Human
B
Modern
Ape
C
Extinct
Hominid 1
D
Extinct
Hominid 2
Scientific Name of Chosen Specimen
Age of Specimen
Location and Date of Fossil Discovery
1.Forehead: more vertical or slopes back
2.Chin: sticks out or recedes back
3.Sagittal Crest: large, small, medium or absent
4.Facial Prognathism: (snout protrusion) large, small, medium, absent
5.Browridge: large, small, medium
6.Dental Arcade: rows of molars parallel or parabolic
7.Canine Tooth: length of exposed upper canine tooth in mm
8.Dental Formula: number of incisors-canine-premolars-molars in upper
jaw (ICPM)
9.Canine Diastema: gap between upper incisors and canines present or
absent
10.Foramen Magnum: towards rear or underneath
11.Width of Cranium: maximum width of brain case in mm
12.Length of Cranium: maximum length of brain case in mm
13. Facial Slope: the angle made by the face and the upper jaw viewed
from side
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