The central theory of biology
Most influential on all aspect of biological research
“Nothing makes sense in biology except in the light of evolution” T. Dobzhanski (1900-1975)
Movement of Alleles in pops. And between generations
“Evolution in Five Stories”
HIV – an evolutionary case studies
The evolution of sex
The 'Dover trial’
What makes mammals mammals?
Genetics of Industrial Melanism
How are black and white phenotype inherited?
Mutant dark (dominant)
Similar: Human brown/blue eyes:
Mutant blue (recessive)
January 21, 2014
Are peppered moth/eye color typical examples for diversity – and selection acting on it?
Can you think of other traits with similar inheritance/diversity?
Skin color, Widows peak, Attached or unattached earlobes, chin
Or traits that differ in diversity, genetics?
Hair color, height
What kind of trait are you thinking of, in the context of selection?
Is the peppered moth a good example to teach/explain evolution?
Many loci greater distribution
The environment has a great impact
Response to Selection
Quantitative Selection Lab
Wisconsin Fast Plants
6 weeks generation time, 2-3 weeks to flowers
HIV – A Case Study for Evolutionary Thinking
Two distinct epidemics
Homosexual men in North America and Western Europe
Heterosexual men and women in South Africa and Southeastern Asia
January 28, 2014
Change RNA to DNA (has to come from the virus)
Virus uses own enzyme to insert itself into the host DNA
RNA DNA transcriptase (reverse transcriptase)
Host-specific to macro-phages, T-cells
AIDS: Acquired Immune Deficiency Syndrome
Treatment with AZT
AZT: Nucleotide analog
Reverse transcriptase mistakes AZT for Thymidine
No viral reproduction
Worked very well for some time
Reverse transcriptase: 50% of DNA-transcripts contain mutations
Mutations in gene fro reverse transcriptase
Some do not mistake AZT for thymidine
Replicate in presence of AZT
New, AZT- resistant strain for HIV
Four steps were involved:
Mutations in reverse transcriptase gene
Mutation result in variability among virions
Some virions survive better in presence of AZT than others
Mutations are passed on to offspring
Genetic composition of HIV population changed over time
Evolution by natural selection
When did mutations occur relative to AZT treatment?
Mutations happen spontaneously and randomly
Selections acts on existing variability
Definition of Evolution
Change of the genetic composition of a population over time
Change of allele-frequencies in a population between generations
Darwin’s 4 postulates of Natural Selection…