Transcript Darwin vs. Lamarck

Day 1
Monday, April 18th
Objectives:
• Explain how biological evolution is the consequence of the interactions of
genetic variation, reproduction and inheritance, and natural selection and time.
• Explain how multiple lines of scientific evidence support biological evolution
Remember to take the genetics test at lunch or after
school if you need to make it up
Agenda:
1. Unit overview
2. Darwin vs. Lamarck
3. Wallace Jigsaw
4. Cartoon Activity
Unit overview
You will be able to…
…compare and contrast the theories of evolution developed by Lamarck and Darwin
…evaluate different types of evidence evolution (biogeography, fossils, homologous structures, vestigial organs
and DNA)
…explain how scientific knowledge can change in light of new evidence
…design a scenario resulting in natural selection and predict its effect on a population of organisms
…address arguments concerning common misconceptions regarding the theory of evolution
We will be able to answer these questions:
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Why is there so much diversity of life on Earth?
How do we know evolution occurs?
What do you need for evolution to take place?
How can we explain why there are fossils of organisms that aren’t alive today?
Activities:
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Evidence Presentations
Variation Lab
Birds and Dots Lab
Model-based Inquiry
Introduction to Evolution
Problem
• What about the animals that no
one had seen before?
• Churches: “extinction” is
blasphemy
• Fossilized creatures didn’t go
extinct…they “changed”
Theory of Acquired Characteristics
Jean-Baptiste Lamarck
1.
Characteristics that get used, develop. Those that aren’t,
get reduced.
L'influence des circonstances (adaptive force)
2.
Characteristics that develop get passed on to the offspring.
Le pouvoir de la vie (complexifying force)
Example (according to Lamarck)
• Giraffes have long necks because their ancestors strained to
reach leaves in trees.
• The offspring had slightly longer necks. Over many
generations, longer and longer necks developed.
Voyage of the Beagle
90 feet long
Malthus
Lyell
Overpopulation
Earth changes over time
Darwin
Struggle for existence
Life can changes over time too
(Some of) Darwin’s Observations:
Plants: well suited to
their environments.
Galapagos: different
climates, different
animals
Alfred Russel Wallace and Controversy
Theory of Natural Selection
Charles Darwin, Alfred Russel Wallace
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All organisms vary in their characteristics.
Organisms always struggle for food, habitat, protection and mates.
On average, offspring that vary in ways favored by the environment will
survive and reproduce more successfully.
Over time, favorable characteristics accumulate in the population
Example
(according to Darwin and Wallace)
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Giraffes have long necks because their ancestors that had necks slightly longer
than average could reach food better than their short-necked relatives.
These longer-necked giraffes got more food, were healthier, and left more
offspring behind.
Darwin/Wallace
Lamarck