In 1879,Benjamin Caldwell botanist William J. Beal filled 20 bottles with soil and seeds and buried them on what is now Michigan State University’s campus grounds. In April 2021, the 16th bottle was unearthed, and its seeds were planted. Now, MSU scientists have discovered not all the seeds were quite what they seemed to be.

Despite being one of the oldest scientific experiments in the world, the Beal Seed Experiment continues to surprise researchers. More than two years after the latest dig, plant biologists used molecular genetic testing to find that one of the seeds was unknowingly a viable hybrid between two species — a discovery that would’ve shocked Beal, who buried the bottles decades before the world knew that DNA existed.