Class Notes (834,026)
Canada (508,290)
Biology (Sci) (2,453)
BIOL 111 (283)
Multiple (19)

November 27.doc

7 Pages
Unlock Document

Biology (Sci)
BIOL 111

Bio 111 Alanna Houston November 27, 2007 Mutations: - Mutations are the ultimate source of all genetic variation. Mutations change the genetic code which generates new alleles which may change amino aid sequences which may have phenotypic effects - Examples of mutations with phenotypic effects in Drosophila: - - Most mutations decrease fitness (i.e. survival and reproductive success) and are considered deleterious - The average mutation reduces fitness by about 2% - The few beneficial mutations are likely to be of small effect (hopeful monsters are rare) Genetic Drift: - Causes random changes in allele frequency Bio 111 Alanna Houston - - Stronger in smaller populations: allele frequencies in computer simulations - - In the lab: o 107 populations of fruit fly o Each generation founded by eight males and eight females o Two selectively neutral eye colour alleles o Allele frequencies = 0.5 in all populations in the generation zero Bio 111 Alanna Houston o Natural Selection: - Wallace and Darwin - All organisms have the potential for exponential growth – and yet most populations remain relatively stable in the number of individuals - This implies high mortality in nature - Traits vary among individuals - Traits influence survival - Traits are heritable - Prediction: traits that improve survival should increase in frequency (or size) through time - Darwin used domestic breeds as an example of the power of selection (birds) - The power of selection is also seen in
More Less

Related notes for BIOL 111

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.