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Module 8 Population Genetics

Lesson 4.8.2

Lesson 2—Causes of Change in the Gene Pool

 

Get Focused


Why are population geneticists so concerned with allele frequencies and whether they’re increasing or decreasing? In general, the more variation there is in a gene pool the better. A population with frequencies of 99% for one allele and only 1% for another allele is in a dangerous situation. The members of the population are so alike that, if the environment were to change to favor the rare allele, there may not be enough of those alleles in the gene pool to produce enough survivors, and the population could succumb to extinction.

 

Domesticated animals (livestock) have been bred to become genetically very similar—producing consistent meat quality and handling traits. However, the lack of diversity in their gene pool means that they are all susceptible to the same types of disease. Similarly, animal populations that are kept isolated in wildlife reserves may suffer the same problem. They can become so similar genetically that they are all susceptible to the same environmental assaults—whether in the form of disease or climate change.

 

Are changes in gene pools positive or negative? What kinds of conditions produce high biodiversity and what conditions do not? In this lesson you will learn about the 5 methods by which these changes occur.

 

By the end of this lesson you should be able to answer to the following focusing questions:

  • What are the causes of change in a gene pool?

  • What factors cause changes in diversity of the composition of a gene pool?

Module 8: Lesson 2 Assignment

Complete the online assignment below

Bio30 4.8.2 online assignment

You should also watch the tutorial video for this lesson and submit a summary. 

Bio30 tut#4.8.2 changes in pop

You must decide what to do with the questions that are not marked by the teacher.

Remember that these questions provide you with the practice and feedback that you need to successfully complete this course. You should respond to all of the questions and place those answers in your course folder.

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