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Printable Handouts
Navigable Slide Index
- Introduction
- Lecture outline
- Foundation of microbial experimantel evolution
- Mendelian genetics
- Darwinian evolution
- Modern synthesis: Mendel meets Darwin
- Classic selection experiments using microbes
- Luria and Delbruck, 1943 (Genetics)
- Typical bacterial growth in lab
- What process leads to mutants?
- Luria and Delbruck's design
- Analysis of the resluts: induced muations
- Analysis of the results: spontaneous muations
- Conclusion: adaptive mutations are spontaneous
- Using microbes to study experimental evolution
- 'Major evolutionary transitions' easily studied
- Modern methods for studying selection
- Modern methods for gauging adaptation
- Evolution of resistance
- Golden era of antibiotics
- End of an era: bacteria resistant to antibiotics
- What happens in the absence of drug selection?
- Schrag et al.: preliminary analyses
- Schrag et al.: results of preliminary analyses
- Schrag et al.: experimental design
- Schrag et al.: analysis
- Proof of compensation for resistance cost
- Schrag et al.: summary
- Evolution of virulence
- Trade-off hypothesis for virulence evolution (1)
- Trade-off hypothesis for virulence evolution (2)
- Can parasites maximize both transmission routes?
- Turner et al.: experimental design
- Turner et al.: analysis
- Balance between virulence costs and benefits
- Bull et al.: predictions
- Bull et al.: experimental design
- Bull et al.: results of preliminary selection
- Bull et al.: experimental results
- Evolution of virulence: summary
- Pathogen emergence
- Phage phi-6 and Pseudomonas bacteria
- Lytic life cycle of phage phi-6
- Cost of host shifting in pathogens
- Duffy et al.: experimental design
- Duffy et al.: gauging phage relative fitness
- Duffy et al.: cost-free emergence in RNA viruses
- How quickly does host specificity evolve?
- Duffy et al.: host specificity results (1)
- Duffy et al.: infection modes of phage phi-6
- Duffy et al.: host specificity results (2)
- Duffy et al.: summary
- Conclusions
Topics Covered
- Experimental evolution
- Classic experiments using bacteria and viruses
- Evolution of antibiotic resistance in bacteria
- Evolution of higher and lower virulence in pathogens
- Evolution of pathogen emergence
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Talk Citation
Turner, P. (2020, September 18). Bacteria and virus evolution: a model for the study of natural selection [Video file]. In The Biomedical & Life Sciences Collection, Henry Stewart Talks. Retrieved December 10, 2024, from https://doi.org/10.69645/NIFJ4479.Export Citation (RIS)
Publication History
Financial Disclosures
- Prof. Paul Turner has not informed HSTalks of any commercial/financial relationship that it is appropriate to disclose.
Update Available
The speaker addresses developments since the publication of the original talk. We recommend listening to the associated update as well as the lecture.
- Full lecture Duration: 43:30 min
- Update Interview Duration: 14:12 min
Bacteria and virus evolution: a model for the study of natural selection
A selection of talks on Infectious Diseases
Transcript
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0:00
Bacteria and virus evolution,
a model for the study of natural selection.
0:07
This lecture covers the following topics.
Experimental evolution of microbes is a relatively new field in biology,
I'll describe how its foundations trace back to
familiar and pioneering work of 19th century scientists,
especially Gregor Mendel's work on genetics and
Charles Darwin's work on evolution by means of natural selection.
By the mid-20th century,
microbiologists had seized upon these ideas in order to use
bacteria and their viruses to test basic biological principles.
I'll then describe several modern examples of how laboratory experiments with
bacteria can be successfully used to
examine questions relating to parasitism and disease.
First, I will discuss the evolution of antibiotic resistance in bacterial pathogens,
a problem of increasing concern to the medical community,
because bacteria can adapt to
overcome drugs that were previously used in combating disease.
Second, I will discuss the evolution of pathogen virulence,
where empirical studies show that the environment can
select for either increased or decreased virulence
(the harm that a parasite inflicts on its host organism).
Last, I will discuss the evolution of pathogen emergence,
which often involves a parasite mutating to infect a new host and
subsequent selection for the parasite to become
better adapted to exploiting its new host.
1:36
I begin with a summary of the many exciting discoveries that
predated modern selection experiments involving bacteria and viruses.
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