On Thurs., March 10, world-renowned evolutionary biologist Dr. Richard Lenski gave a presentation entitled “Time Travel in Experimental Evolution” in the Skogen Auditorium of Centennial Hall on his famous, 28-year old, ongoing bacterial evolution experiment.

Dr. Lenski is the John Hannah Distinguished Professor of Microbial Ecology at Michigan State University. He is a member of the National Academy of Sciences as well as a former president of the Society for the Study of Evolution. He has authored over 150 scientific articles, and his work has appeared in many scientific textbooks and has been featured in the New York Times, New Scientist, Nature, Scientific American and MSNBC.

Beginning in 1988, Dr. Lenski’s research project with the bacteria, Escherichia coli, has been an ongoing project for over 25 years. Dr. Lenski and his lab assistants have cultured over 64,000 generations of E. coli, and along the way, have made some quite profound scientific discoveries in the subjects of biology, evolution, and genetics.  

The basis for Dr. Lenski’s research stems from some fundamental, age-old questions regarding evolution and the emergence of traits over time. Since E. coli are fast reproducers, they allowed Lenski and his colleagues to be able to culture and grow them repeatedly and then observe changes in their gene sequences over time.

“We froze some of the generations of E. coli, and what we were able to do is observe changes in their genomes when compared to earlier generations. So not only are we able to watch evolution proceed in the forward and compare it to the reverse direction, but we are also able to replay evolution from particular points of interest to test whether an outcome depended on certain prior events, or alternatively, could have happened at any point in time,” said Dr. Lenski.

One of the most significant events during Dr. Lenski’s research happened when they discovered that a population of E. coli near generation 30,000 was able to use citrate, a derivative of citric acid, in their metabolic cycles, which is something that none of the populations in previous generations were able to do. This discovery provided striking implications in regards to the mechanisms that are causing evolution to occur over time.

Throughout the course of his 28-year experiment, Dr. Lenski and his team have cultured nearly 40 trillion cells of E. coli and have observed some noticeable discoveries along the way. Dr. Lenski is hopeful for the results that will be seen in the years to come.

“My life’s goal with this entire project is to hand it down to someone after I pass and for that person to hand it down, and so on. I want to keep this experiment alive and progressing so that generations after myself can witness evolution in action like my team and I have been so fortunate to see,” said Dr. Lenski.

Would you like to learn more about Dr. Lenski’s experiment? His research website can be visited at http://myxo.css.msu.edu/index.html. He also has a blog, which can be viewed at https://telliamedrevisited.wordpress.com.