What
evidence for evolution can be gathered from a comparative analysis of the
limbs of the baboon, seal, and humans?
Grade
Levels: 11th and 12th
Learning
Standard: NYC Performance Standards S4, S5, S6, S7 & S8
Time
Requirement: approximately 90 minutes preparation tie and 135 minutes
class time
Topics
Covered by this Lesson: evolution, adaptation, analogous and homologous
structures, natural selection
Pre-Visit:
Objectives:
Make a connection between the understanding to be taught and the interests/experiences/needs
of the students. Elicit from students the question that needs to be
answered, the problem that needs to be solved by this understanding.
Introduce discrepant events/situations in which prior knowledge is shown to
be inadequate.
Examples:
Play telephone ; with the class
by whispering a short message written on paper to a student who will then
pass the message on to the next student and so on. Have the last student
to receive the message say it aloud to the class. Reread the original
message and discuss how it came to its final altered state.
Write a description of how small changes over the years may result in something
very different that the original object, such as a house that has been added
on to, renovated and painted differently.
Materials
Required: drawing paper, color pens, diagram of Equus
Student Learning Prerequisites:
Students
should understand the scientific method of scientific investigation.
The
general themes of Biology:
Visit:
Students will visit the zoo with a notepad and pen. Their aim would
be to look closely at the limbs of the monkey, seal, and that of their fellow
students. They should try to draw the limbs best as possible, recording
in what environment each of the above organisms lives. How is the limb
used for movement? How is the limb adapted to their environment?
What function does the organism perform with his limb? Superficially,
how do the limbs differ? How are they the same? If we were to
switch limbs from one organism to another, how would this affect the organism?
Post
Visit:
Assessment:
assess students' ability to explain the major understanding of
this lesson in their own words by writing an essay. Content based, multiple
choice questions for conceptual understanding. Content and real-world
application, extended constructed-response. Example, ask students to
place drawings of the monkey, seal, and human limbs in their evolutionary
order. Ask them to explain why they have chosen this particular order.
Based on this order what would they expect humans to look like in two million
years from now and explain why.
Extensions
and suggested homework assignments:
Fossils indicate that during the Eocene epoch 37 to 55 million years ago,
camel had small body size, four toed feet and low crowned teeth. In
contrast, modern species of camels are larger and have evolved two toed feet
and high crowned teeth. Write an essay describing how the ancestral
camels may have evolved physically over these million of years to become our
present day camels. Include in your essay adaptive characteristics that
might have favored some of the changes.
Possible
Questions that may be brought up: