Testing of mitochondrial and nuclear DNA revealed the ancient cats evolved into eight main lineages that diverged in the course of at least 10 migrations ( in both directions ) from continent to continent via the Bering land bridge and the Isthmus of Panama , with the Panthera genus being the oldest and the Felis genus being the youngest .
There were at least 10 migrations ( in both directions ) from continent to continent via the Bering land bridge and Isthmus of Panama .