Transcript Breeding Larkeys - Home - SVSD SharePoint Web Site

Natural
Selection
SURVIVAL OF THE FITTEST! 
Natural Selection
(from Charles Darwin)
 Three
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main parts:
1. Nature produces variation.
2. Life is a challenge.
3. Organisms in a population compete.
ONLY THE STRONGEST SURVIVE!
SURVIVAL OF THE FITTEST! 
Two More Definitions…
 Selective
Pressure: Environmental
pressures on a population.
 Biological
Evolution: Process of change
that results from natural selection.
Review Population Change
 What
will happen with Larkey populations
in a new environment?
 Will all the Larkeys survive?
 Will the Larkeys maintain the same level of
variation in their population?
 Will the population change in response to
the change in the environment?
Analyze the Data
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1. What features of Larkeys affected their survival?
2. What traits helped Larkeys survive when they
moved to the prairie environment?
3. What traits helped Larkeys survive when they
moved to the forest environment?
4. What factor in the environment affected the
survival of Larkeys?
5. What effect did predation have on the
population?
6. What caused the change in the population?
7. How does removing certain individuals from the
population increase the number of individuals with
other traits?
Selective Pressure
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8. The coyotes in the prairie put pressure on
the prairie Larkey population. The bobcats in
the forest put pressure on the forest Larkey
population. How did this pressure change the
Larkey population?
9. Which traits were adaptations that helped
prairie Larkeys survive the pressure?
10. Which traits were adaptations that helped
forest Larkeys survive the pressure?
Connect to Walkingsticks
 1.
What selective pressure was brought
on the population of walkingsticks?
 2. In what way did the population
change over time?
 3. In what ways are the populations of
Larkeys and walkingsticks similar?
 4. When a trait disappears from a
population, is it gone for good, or can it
come back? Explain…