DNA

The Y chromosome is passed from father to son remaining mostly unaltered across generations, except for small traceable changes in DNA. By tracking these changes, we constructed a family tree of humankind where all male lineages trace back to a single common ancestor who lived hundreds of thousands of years ago. This human tree allows us to explore lineages through time and place and to uncover the modern history of your direct paternal surname line and the ancient history of our shared ancestors.

https://discover.familytreedna.com/y-dna/Q-L275/story