Transcript Evolution & Selection

Evolution & Selection
Modified from parts of a presentation by Diane Ebert-May
Michigan State University
Where does life come from?
• Where do we come from? - one of ultimate
human questions
• One of humanity’s traits is to ask, and try to
answer, such questions – stories of Creation…
• With more knowledge, more understanding,
our ideas change – tools of science
What is Evolution?
• In your notes – write down words or phrases
that come to mind when you hear this word
• Share your ideas with your group members,
and combine ideas to create a definition you
can share with the class.
What is Evolution?
• Simple biological definition:
– “Change in the frequency of genes and
chromosome configurations in a population.”
(Wilson ch. 6, p. 75)
– What does this mean?
– Discuss in your group, & come up with an answer
(or a question).
What drives evolution?
• Wilson ch. 6
• Our main topic for today
Write a scenario that explains the phenotypic changes in the trees and
the animals. Use your understanding of evolution by natural selection.
Selective Agents or Forces:
• Artificial selection (selective agent is?)
– Humans
• Natural selection (selective agent is?)
– The Environment
• Genetic drift (there is no selective agent…)
– Occurs by chance – random change
Wrap-Up: At what “levels” do selection
& evolution occur?
• Look at your hierarchy of terms linking DNA to
species
• Where would you add the term “population?”
• Which level in this hierarchy gets selected for
or against by the selective agents we’ve
discussed today?
• Now - at what level does evolution occur?
Write a scenario that explains the phenotypic changes in the trees and
the animals. Use your understanding of evolution by natural selection.
Make your own notes, then come up with one written response for your
group that all agree upon & understand. Put original in folder.