Inside the World's Longest-Running Evolution Experiment

If we rewound the tape of life, would life as we know it evolve the same way?
Derya Ozdemir

We define evolution as the gradual change in the heritable features of biological populations over consecutive generations and think of it as a slow process. So, while variables such as climate change, habitat destruction, pollution, and others can quicken its pace, we seldom see evolution in action in our daily lives.

That's what makes YouTube channel Veritasium's latest video so special. It's centered around the world's longest-running evolution experiment: the E. coli long-term evolution experiment (LTEE), an ongoing experimental evolution study led by Richard Lenski, a professor of Microbial Ecology at Michigan State University, who has been tracking genetic changes in 12 initially identical populations of asexual Escherichia coli bacteria since 1988.

This experiment is particularly insightful since these bacteria go through six or seven generations every day, which means that after 33 years, the bacteria in the flasks will have reached generation 74,500. "If those were human generations, it would represent 1.5 million years of hominid evolution," says Muller. Imagine that!