Class Notes (838,933)
Canada (511,158)
Biology (1,140)
BIOL 1004 (106)

Patterns of Selection

2 Pages
Unlock Document

BIOL 1004
Tamy Superle

(Pages 194 – 207) 6.3. Patterns of Selection: Testing Predictions of Population Genetic Theory Selection on Recessive and Dominant Alleles  This chapter covers the mathematics behind the evolution of populations. Read the book because I can’t explain numbers in words. Chapter 6 (Pages 210 – 218) 6.4 Mutation Adding Mutation to the Hardy – Weinberg Analysis: Mutation as an Evolutionary Mechanism  Mutation by itself is generally not a rapid mechanism of evolution. o For example in a population with a frequency of 0.9 for A alleles and a frequency of 0.1 for a alleles, a mutation rate of 1 per 10 000 (a high rate of mutation) would result in frequency of 0.89991 for the A allele and frequency of 0.10009 for the a allele.  This number is very similar to the original frequencies of alleles within that given population.  Therefore, it would take 1000 generations for the allele frequency for A to change from 0.9 to 0.81.  Mutation can cause substantial change in allele frequencies but it does slowly.  See Page 211 for clarification and the math shown Mutation and Selection  It is not correct to assume that mutation is unimportant because of its unappreciable changes in the allele frequencies of a population  Mutation combine with selection can become a crucial piece of the evolutionary process. o Read experiment on page 212 and 213. o The experiment shows that while mutation itself is only a weak mechanism of evolution, it nonetheless supplies the raw material on which natural selection acts. o Mutation is the ultimate source of genetic variation. Mutation-Selection Balance  Most mutations are deleterious.  Selection acts to eliminate such mutations from populations.  Deleterious alleles persist, however, because they are continually created anew.  When the rate at which copies of a deleterious alleles are being eliminated by selection is exactly equal to the rate at which new copies are beings created by mutation, the frequency of the allele is at equilibrium  mutation-selection balance.  What is the frequency of the deleterious allele at equilibrium? o ^q = √(µ/s) *The ^ should be on top of the q. o µ is the mutation rate and s is the selection coefficient (between 0 and 1) which
More Less

Related notes for BIOL 1004

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.