EvoS Seminar Series: Time Travel in Experimental Evolution

Zoom link: https://binghamton.zoom.us/j/98942256738
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Abstract:
Like cuneiform on clay tablets, the history of life itself is written in minerals and in code. The minerals are fossils of long-dead organisms, and the code is the language of DNA that reveals the family tree of life. But evolution is not only about the past—it is a process that continues to this day. In fact, evolution can be studied experimentally in organisms, like bacteria, with fast generations. Moreover, bacteria can be frozen and revived, allowing one to compare and even compete cells that lived at different times. In this talk, I will present highlights from an experiment with bacteria that has been running for over 30 years and 75,000 generations. I will also show vignettes from experiments with viruses that infect bacteria, and with digital organisms that can solve logic problems. These experiments collectively illuminate both the gradual improvement of performance and the sudden emergence of new capabilities.

BioSketch:
Richard Lenski is the John Hannah Distinguished Professor of Microbial Ecology at Michigan State University, where he studies the genetic mechanisms and ecological processes that are responsible for evolution. Unlike most evolutionary biologists, Lenski performs experiments to watch evolution in action. In an experiment that he started in 1988, he and his team have followed 12 populations of bacteria while they evolve in the lab for 75,000 generations, providing insights into the process of adaptation by natural selection, the dynamics of genome evolution, the repeatability of evolution, and the origin of new functions. Samples from throughout the experiment have been stored in a freezer, and the organisms that lived in different generations can be revived and directly compared—in effect, allowing time travel. In addition to his research on bacteria, Lenski studies the coevolution of bacteria and viruses that infect bacteria, as well as digital organisms in the form of computer programs that can self-replicate, mutate, compete, and evolve the ability to solve problems.

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Lenski is a past President of the Society for the Study of Evolution, and he was a member of the National Research Council committee that reviewed the scientific approaches used in the FBI’s investigation of the 2001 anthrax attacks. He co-founded the BEACON Center for the Study of Evolution in Action, which brings together biologists, computer scientists, engineers, and philosophers to harness and illuminate the power of evolution in action. Lenski has been awarded fellowships from the Guggenheim and MacArthur Foundations, and he received a Friend of Darwin award from the National Center for Science Education. He is a member of the National Academy of Sciences, and a fellow of the American Academy of Microbiology, the American Academy of Arts and Sciences, and the American Philosophical Society. Lenski has authored over 250 papers, and he has mentored some 30 graduate students and postdoctoral scientists who are now on the faculties of universities around the nation and the world.

Accompanying Reading:

Lenski, R.E., 2017. What is adaptation by natural selection? Perspectives of an experimental microbiologist. PLoS genetics 13(4), e1006668.

Link: https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1006668

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