Agnirva Space Premier League - Expedition #31468: How Microgravity Shapes the Genetic Evolution of Bacillus subtilis in Space

What happens when life evolves outside of Earth’s natural environment? Scientists aboard the International Space Station (ISS) are exploring this fascinating question by investigating how populations of Bacillus subtilis—a common and well-understood bacterium—mutate and adapt when grown in microgravity over multiple generations.

Led by Dr. Craig Everroad from NASA Ames Research Center, this study follows a process known as experimental evolution. In a controlled environment aboard the ISS, populations of Bacillus subtilis are cultured over extended periods to track genetic changes, evolutionary pressures, and adaptive strategies. Researchers are especially interested in mutation rates, how natural selection acts in a gravity-free environment, and whether these microbial populations develop traits that could be beneficial—or harmful—over time.

The unique conditions of space—microgravity, radiation exposure, and limited nutrient availability—make it an excellent testing ground to uncover the rules of evolution in extreme environments. Understanding these rules has real-world applications. It can inform how we prevent bacterial contamination during long-duration space missions and help in designing resilient biological systems for biomanufacturing or medical use in space.

By sequencing the genomes of bacteria grown on the ISS and comparing them with Earth-based controls, scientists are gaining new insights into how quickly evolution occurs in space and what types of mutations are most common. This experiment spans several ISS expeditions and leverages long-term observation, ensuring a robust data set.

For students and future scientists, this research opens up an exciting intersection of microbiology, genetics, space science, and evolution. It illustrates how even tiny organisms can help us answer some of the biggest questions about life beyond our planet.

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