It seems some of the scientific discoveries that have dramatically changed our lives over the years still remain mysteries. Take the disappearance of ancient Europeans. Scientists recently analyzed 37 skeletons discovered in Central Europe and dating between 7,500 and 2,500 years ago, revealing that the genetic lineage was transformed approximately 4,500 years ago. More study showed that these ancestors had dark skin and light eyes, but researches are still unable to pinpoint what caused these radical changes. Learn more about nine other crazy discoveries that science can’t explain in this edition of Hybrid Librarian.