Who discovered the germ theory of disease and what developments in evolutionary biology did that coincide with? 

Louis Pasteur suggested that microorganisms are the cause of infectious illness. This helped identify pathogens, discover antiseptic techniques, and discover antibiotics. The germ theory was proposed a year before On the Origin of Species was published.

    What contributed more to the declining death rate from tuberculosis? Drugs, sanitation, or nutrition?

All 3, but more recently…Drugs, antibiotics

Genome composed of 8 RNA strands that encode 11 proteins: polymerases, structural proteins, and coat proteins.

    Does the human immune system lead to evolution by natural selection in influenza A viruses?  If so, how?

Yes, the antigenic sites of the virus’ proteins must be novel in order for them to penetrate host cells.

    How fast does influenza A evolve and how was this studied?

6.7x10^-3 nucleotide substitutions/nucleotide/year. Frozen flu samples were sequenced for the hemagglutinin gene between 1968 and 1987.

    Do a diverse assemblage of flu strains survive from year to year?  Which ones survive?

No, only propagules of strains with a novel mutation in the antigenic site that allows survival in hosts.

  How would you predict next year’s flu strain?

The strain most likely to have surviving descendents is the currently circulating strain with the most mutations in the 18 codons known to be under positive selection.

  Where did the 1968 flu strain come from?

An H3 was newly acquired from a nonhuman strain that allowed the 1968 flu to infect huge numbers of people. It came from birds.

  Why is there such diversity in virulence?      

1)   The coincidental evolution hypothesis – the virulence of many pathogens is due to an accidental by-product of selection on other traits

2)   The short-sighted evolution hypothesis – traits that enhance within-host fitness of pathogen strains may rise to high frequency

3)   The trade-off hypothesis – Natural selection should favor pathogens that strike an optimal balance between the costs and benefits of harming their hosts.

  What were paul Ewalds predictions about the evolution of virulence in human pathogens?

1)   Diseases transmitted by direct human contact cannot afford to be virulent, but vectorborne diseases can afford to be highly virulent.

2)   Bacteria contaminated water can play the same role of a vector in his first prediction.

   Discuss why it might be useful to study cancer as an evolutionary process in an evolving population of cells.

? Cancer cells have mutations in genes affecting cell cycle regulation. 

  Do malignant tumors have greater or lower allelic diversity? 

Greater

We alter our own environment at a rate that outpaces evolution by natural selection. Many diseases strike late in life.

 What evidence suggested that breast cancer might be partly a viral disease?

Mice have a virus MMTV that causes an equivalent to breast cancer. Over 1/3 of human breast cancer tissue samples in a study had MMTV like sequences.

Mus domesticus (Western Europe) has a higher frequency of MMTV than Mus musculus (Eastern Europe). If MMTV causes breast cancer in humans, the rate of breast cancer should be higher in countries with Mus domesticus than in countries with Mus musculus.

 Why might breast cancer be seen as a disease of human civilizations?

Lack of concrete evidence for the MMTV hypothesis leads to this conclusion.