ritical Thinking Assignment Essay Ardi and Lucy
Why do many paleoanthropologists classify Ardi (Ardipithecus ramidus) and Lucy
(Australopithecus afarensis) as hominins?
Write a double spaced two- page essay and on a third page list any references. Topic:
Bipedalism (The status of bipedalism in two genera of fossils that lived more than one million
years apart from each other.) Type in FONT SIZE 10 or 12. 1 inch margins top and bottom, right
and left.
1. Write one page of the essay (25 points) on Ardipithecus ramidus who lived 4.4 million
years ago
Imagine you have a complete skeleton of a modern human and a chimpanzee (See p
208-209 Figure 8-17) with you in a laboratory as you analyze Ardi. The photo of the
Ardi skeleton on p. 214 shows that the following were found and, so that is what you
have for comparison: Skull and teeth, Upper limb and hand, Pelvis, Lower limb and foot.
Which parts are more similar to the chimpanzee? Which are more similar to the human
not only in the structure, but also in how the hand or foot was used?
(AAAS) American Association for the Advancement of Science publishes the scientific
journal SCIENCE. Some helpful summary pages are on the hands, pelvis and femur and
the foot. READ these BEFORE BEGINNING YOUR ESSAY. They are a primary source.
Be very specific as to what parts of the skeleton and the shape of which bones or the
existence of particular unexpected bones that result in the description of Ardi’s ability to
move in two environments.
What evidence overturned a hypothesis about our Last Common Ancestor (LCA)
and shown it to be wrong? What evidence overturned the Savanna hypothesis?
2. Write one page of the essay (25 points) on Australopithecus afarensis who lived about 3.2
million years ago. What parts are the Lucy skeleton similar to a chimpanzee? What parts are
similar to a modern human?
Australopithecus afarensis includes:
a.) the famous skeleton, “Lucy” found at Hadar, Ethiopia,
b.) the three year old infant found at Dikika, Ethiopia and
c.) the 3.7 million year old footprints found in volcanic ash plus fossil bones found at Laetoli,
Tanzania.
Be sure to include important information from a) b) c) above.
On page 3 list any references you used. www. Purdue OWL: Chicago Manual of Style 16th Edition
Example:
Lovejoy, C.O. et al. “Careful Climbing in the Miocene: The forelimbs of Ardipithecus ramidus and
Humans Are Primitive.” SCIENCE. 2 Oct. 2009: 70. Print
Lovejoy, C.O. et al. “Combining Prehension and Propulsion: The Foot of Ardipithecus ramidus.”
SCIENCE. 2 Oct. 2009: 72
Lovejoy, C.O. et al. “The Pelvis and Femur of Ardipithecus ramidus: The Emergence of Upright
Walking.” SCIENCE. 2 Oct. 2009: 71
