American biologist Richard Lensky conducted a groundbreaking experiment in 1988, despite facing criticism from creationists. The experiment involved cultivating 12 populations of identical bacteria in separate containers to observe their evolution. What was initially planned as a short-term project has now been ongoing for over 35 years, with the team from Michigan State University tracking the bacteria through approximately 75,000 generations. This is equivalent to the evolutionary timescale of the human race over 1.5 million years.
The research by Spanish biologist Alejandro Kusa from the Polytechnic University of Madrid, along with his colleagues, suggests that evolution may be predictable in the short term. Their study published in the journal Science reveals that up to 75% of the initial adaptive changes in bacteria can be predicted.
Lensky and his team have focused on studying Escherichia coli bacteria, which naturally resides in the human intestines. During the experiment, one of the 12 populations of bacteria, after reaching its 31,500th generation, developed the ability to consume sodium citrate, resulting in the emergence of a new species.
The Lensky experiment holds significant importance as frozen samples of each 500th generation of bacteria have been preserved since 1988. This enables biologists to explore the evolutionary changes that have occurred over time, providing insights into alternate paths of evolution.
However, Lensky cautions that laboratory conditions differ from the complex natural environment affected by factors such as climate change and various interactions. Thus, he advises against drawing premature conclusions regarding the predictability of evolution in nature, although he acknowledges the significance of the new research findings.
Kusa and his team hope that their work will contribute to predicting the evolution of pathogens and pests in the future. Additionally, their findings could help guide the selection of antibiotics to prevent bacterial resistance. This study underscores the importance of understanding evolutionary processes in addressing medical and biotechnological challenges.