Lesson Focus: This lesson plan will introduce students to the discovery of genus Ardipithecus, and to common terms used when discussing prehistory and early humans.
Grade Level: Grades 7-8
Time Needed: Two or three class periods depending on class length and access to internet.
Vocabulary Words: hominid, archaeologist, anthropologist, paleontologist, artifact, fossil, radiocarbon dating, Australopithecus afarensis, Ardipithecus ramidus, bipedal, nomad.
Lesson Outline:
1. Begin the lesson by introducing the term prehistory and what it covers:
- Prehistory is the story of humankind before writing was developed. History begins when writing was invented, about 5,500 years ago.
- Prehistory discusses hominids; group of early humans and human like creatures which preceded them.
- Go over vocabulary.
2. Next, discuss established theories and how they have changed with new discoveries.
For decades, the oldest known hominids belonged to the genus Australopithecus. Australopithecus were believed to have existed around 4.4 million years ago and were bipedal. The most famous Australopithecus is Lucy, a hominid skeleton unearthed in 1974 Hadar, Ethiopia. Named for the Beatles song “Lucy in the Sky with Diamonds”, she is 3.2 million years old and, although curved fingers indicate she still climbed trees, could walk upright. She belonged to the species named Australopithecus afarensis, which means southern ape from Afar. Hadar is located in the Afar region of Ethiopia. Lucy and other Australopithecus did not use tools.
Follow this link for more information on Lucy and other Australopithecus.
In 1992, south of Hadar at a site called Aramis, this belief was changed when a Japanese paleontologist named Gen Suwa found a molar belonging to an even older hominid. Suwa, Professor Tim White from the University of California, and a twenty person team uncovered fossils from seventeen individual hominids over the next few years. Analysis put these at about 4.4 million years old. Fossil characteristics revealed them to be evidence of a new genus and species, Ardipithecus ramidus. Ardipithecus ramidus comes from the Afar language; Ardipithecus means ground ape and ramidus means root.
One female skeleton has been nicknamed Ardi and The Discovery Channel produced a documentary, Discovering Ardi, detailing the discovery and fossil analysis.
Characteristics that make Ardipithecus distinctive include:
- Ardipithecus has both ape and human characteristics.
- Ardipithecus was capable of walking upright and climbing in trees with a big toe capable of gripping.
- The Ardipithecus’ brain is around same size as that of Australopithecus and modern chimpanzees. Brain size does not appear to be linked to becoming bipedal.
- Through analysis of plant and animal fossils in the region, it was determined Aramis was a lush, humid woodland when Ardipithecus lived there. This disputes the theory that hominids became bipedal on an open savannah.
- Unlike apes, the canine teeth are smaller and non-projecting.
- To some scientists this alteration indicates a shift in social behavior and mate selection. Males flashing prominent canines in a display of aggression and dominance might have lost its appeal to females.
Follow this link for more information on Ardi and other Ardipithecus.
3. Divide the class into several groups and designate each group as either Ardipithecus ramidus or Australopithecus afarensis. Using their textbooks, the web-sites above, and what they learned in class, have each group design a web-site listing specifics about their assigned hominid. If your school does not have this kind of internet set-up, the students can create pamplets, posters, or flyers. Also, Weebly.com allows teachers to create free class sites where individual students can create their own password protected sites.
Their finished work should contain following information:
What did an Ardi or Lucy look like? (How tall, facial features, hair, etc.)
Where did they live?
Describe their environment.
What did they eat?
How did they get their food?
How did they get around?
Did they use any objects as tools?
Did they make their own tools?
Where were the first fossils of their type found? When?
Who found the fossils? Describe and name that person’s occupation?