For this exercise you will read ‘Evolution in Action: a 50,000-Generation Salute to Charles Darwin’, one of a series of articles celebrating the 150th anniversary of the publication of Darwin’s Origin of Species published by the American Society for Microbiology. This one features the research of Richard E. Lenski and colleagues of Michigan State University designed to investigate natural selection experimentally in the lab and through computer simulations. You can access the review here. Read it and be prepared to answer these questions.

1.(2) A contemporary of Darwin’s, the Reverend William Dallinger, was probably the first person to test theories about natural selection using microorganisms. What was the design of his experiments and what did they demonstrate?

2.(2) Look up Luria and Delbrück’s famous 1943 experiment on the origin of adaptive traits in bacteria and explain how it shed light on how natural selection works. 

3.(2) Describe in general the design of Lenski’s 50,000-generation experiment with bacteria. What hypotheses is it designed to test? 

4.(2) Describe one of the unexpected results of Lenski’s experiments.

5.(2) What are avidians and what did Lenski learn from them?