Download Learning Guide: Natural Selection, Genetic Drift and Gene Flow

Learning Guide: Natural Selection, Genetic Drift and Gene Flow
Bill Activity #7
To Think About: How is natural selection, genetic drift and gene flow major mechanisms of
evolution?
1st Read About: Natural selection, genetic drift and gene flow Pgs. 476-485
Campbell’s Biology, 9th edition (Title your notes in your BILL notebook. Also please
use “2-sided column notes” or Cornell style format with the key points on the left
and the notes on the right, feel free to leave space at the bottom of each page to
write a summary, also add color and highlighting for the important ideas and key
points. These are your notes you will be using for in class discussions and studying
from.)
❑
List the three major mechanisms that alter allelic frequency directly and cause most
evolutionary change. Describe what conditions they violate.
❑
Natural Selection.
o Briefly describe natural selection and how it can cause adaptive evolution.
Include an explanation of how natural selection results in an increase in the frequency
of beneficial alleles and a decrease in the frequency of deleterious (harmful) alleles.
o Describe how fruit flies have become resistant to insecticides
❑
Genetic Drift.
o Describe the process of genetic drift.
o Certain circumstances can result in genetic drift having a significant impact on a
population. Two examples are the founder effect and the bottleneck effect. Describe
each process with supporting information.
o Read and summarize the Greater Prairie Chicken Case Study.
o Explain the four key points of genetic drift using real world examples.
o Explain why genetic drift takes place less often in large populations.
❑
Gene Flow.
o Describe the process of gene flow, include example
o Distinguish genetic drift from gene flow in terms of how they occur and their
implications for genetic variation in a population.
❑
Discuss how natural selection is the only mechanism that consistently causes adaptive
evolution.
o Describe relative fitness and give an example.
o Sketch and explain each of the selection graphs
o Describe how natural selection is the key role in adaptive evolution and give an example
o How does the process of sexual selection and reproduction affect the reproduction
process? Include an explanation of sexual dimorphism and intrasexual selection,
intersexual selection.
o Explain two ways that genetic variation is preserved in a population.
o Discuss what is meant by heterozygote advantage, using sickle cell anemia as an
example.
nd
2 Interact…Watch Mr. Andersen’s Genetic Drift video.
❑
Draw arrows on the attached concept map and answer the video questions. Feel free to add
additional notes on the video guide as needed.
Supplementary Resources:
● Crash Course’s Population Genetics video.
● Kimball’s Biology Pages: The Hardy-Weinberg Equilibrium
● Genetic Drift Simulation at the University of Arizona
Learn More:
To learn more about genetic drift, use the links below:
Brief video tutorial about genetic drift (Lego people!)
UC Berkeley’s Understanding Evolution: Genetic Drift
PBS’ Evolution site: The Founder Effect and Polydactyly
Genetic drift simulator at UConn