UIUC IB 201 - POPULATION GENETICS (13 pages)

Previewing pages 1, 2, 3, 4 of 13 page document View the full content.
View Full Document

POPULATION GENETICS



Previewing pages 1, 2, 3, 4 of actual document.

View the full content.
View Full Document
View Full Document

POPULATION GENETICS

55 views

Other


Pages:
13
School:
University of Illinois at Urbana, Champaign
Course:
Ib 201 - Genetics and Evolution
Genetics and Evolution Documents

Unformatted text preview:

7 7 1 POPULATION GENETICS INTRODUCTION Most humans are susceptible to HIV infection However some people seem to be able to avoid infection despite repeated exposure Some resistance is due to a rare allele of a gene that codes for the CCR5 protein CCR5 is a cell surface protein that is a co receptor for the HIV virus when it binds to the cell membrane of macrophages and T cells Some people have a form of the gene encoding CCR5 that includes a 32 bp deletion that results in a dysfunctional protein The allele is called CCR5 32 Individuals who inherit two copies of the deleted allele have no CCR5 co receptors on the cell membrane of white blood cells These homozygotes are highly resistant to HIV infection Will the global HIV epidemic result in increasing frequencies of the CCR5 32 allele If so how soon will this happen Also northern European populations carry a higher frequency of this allele than do Asian or African populations Is this difference due to chance or due to the fact that CCR5 32 also increased resistance to some previous epidemic that occurred in Northern Europe plague smallpox etc These are kinds of questions that po p ul atio n ge neti cs is designed to answer This discipline describes the behavior of alleles in populations by focusing on the forces that can cause allele frequencies to change over time Allele frequency change over time is simply a definition of evolution So population genetics is that branch of genetics that is concerned with the evolutionary processes of natural selection genetic drift mutation migration and non random mating Population genetic approaches can be used to understand the consequences of these processes individually or in combination Review A p op ul ati on is a group of organisms of the same species living within a prescribed geographical area The area is usually determined to be of a size within which individuals are likely to find mates Geographically widespread species are often subdivided into more or less distinct



View Full Document

Access the best Study Guides, Lecture Notes and Practice Exams

Loading Unlocking...
Login

Join to view POPULATION GENETICS and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view POPULATION GENETICS and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?