1. HOMINID CRANIUM COMPARISON (The “Skulls” Lab)

2. Objectives:
Describe, measure and compare cranial casts or drawings from contemporary apes (chimpanzees and gorillas), modern humans and fossil “hominins” (erect and bipedal forms evolutionarily separated from apes). (“Hominid” is the new collective term for African apes and humans).
The purpose of the activity is for you to discover what some of the similarities and differences are that exist between theses forms, and to see the pattern of the gradual accumulation of traits over time, leading to modern humans.

3. Concepts
Documenting similarities and differences between species is fundamental to understanding their biological and evolutionary relationships.
Transitional forms in an evolutionary sequence are generally mosaic; some traits evolve more rapidly than others.
Modern humans have not evolved from modern apes: both have evolved from a common ancestor

4. Objectives:
Identify the appropriate skeletal and dental features and landmarks required for the measurements and descriptions.
Describe features of a given specimen as either similar to, different from or the same as those present in another specimen.
Recognize the sequence pattern in which several human skull features appeared over time.

5. Procedure:
Humans can be used as evidence to support the idea that modern species are evolutionarily related to one another and descended from now –extinct non-modern forms.
You should have a copy of the Hominid Cranium Comparison Checklist because the details of each measurement and observation are spelled out on it. Create you own data worksheet for recording descriptions and measurements.

6. Label the columns on your data worksheets with the names of each specimen. Simply number the left hand edge of the worksheet 1 through 18 to correspond to the 18 items on the checklist (This will put all entries for a single checklist item on the same line across the page to facilitate comparisons).

7. Measure and described the specimens
Measure and described the specimens. Determine and describe the patterns represented by your findings.
Simply list those features that all of the specimens have in common
Identify those features which are most useful for distinguishing between the specimens
Describe the changes that occur in only the hominin crania over time

8. CHECKLIST HOMINOID CRANIUM COMPARISON
PLEASE READ THESE 5 STATEMENTS BEFORE BEGINNING THIS ACTIVITY:
1.- Work in group of 3-4 students so that everyone can be involved in the activity.
2.- BE SURE (!) TO TAKE TURNS doing different measurements and observations.
3.- When taking a measurement, use the SLIDING CALIPERS (except for #11 & #12 which may require the HINGE calipers) and remember to…..
4.- ALWAYS MEASURE IN MILLIMETERS (mm) and round off to whole numbers.
5.- PLEASE DO NOT ADD ANY PENCIL OR PEN MARK ‘TATTOOS’ TO THESE CRANIA, OR STICK YOUR FINGERS IN THEIR EYE ORBITS OR NOSES!