Bacteria in lake mendota evolve seasonally, echoing past eras

Bacteria in Lake Mendota, Wisconsin, evolve in an endless cycle, reacting to changing seasons, reports IFLScience. Research conducted by scientists from the University of Texas at Austin shows that these bacteria evolve throughout the year, adapting to seasonal environmental changes.

In winter, the lake is covered with ice, while in summer, it is filled with algae. These changes affect the bacteria, which must adapt to low water temperatures in winter and challenging conditions in summer. Scientists conducted their experiment for nearly 20 years, analyzing 471 microorganism samples collected over this period. The project demonstrates that genetic variability is common and frequent, with cyclic seasonal patterns observed in 80% of the samples.

Many species of bacteria appear to evolve backward, returning to a genetic state from thousands of generations ago. Microbes have a lifespan of only a few days, allowing the analysis of thousands of generations of evolution within a year.

"I was surprised that such a large portion of the bacterial community was undergoing this type of change," said Robin Rohwer, a researcher at the University of Texas at Austin.

In 2012, the lake experienced unusual weather conditions. An extremely hot and dry summer caused earlier-than-usual ice melt and reduced water inflow, decreasing the number of algae. These changes significantly impacted the life processes of bacteria, particularly nitrogen metabolism. Understanding these phenomena was crucial for better understanding the evolutionary processes of microorganisms in this ecosystem.

Research published in Nature Microbiology emphasizes that ecology and evolution are closely linked. Understanding this process can benefit studies of microorganisms and their role in ecosystems.