Source google image: https://upload.wikimedia.org/wikipedia/commons/thumb/3/32/Human_genetic_isolation_by_distance_in_Kanitz_2018.png/350px-Human_genetic_isolation_by_distance_in_Kanitz_2018.png
Isolation wikipedia
Source google image: https://upload.wikimedia.org/wikipedia/commons/thumb/3/32/Human_genetic_isolation_by_distance_in_Kanitz_2018.png/350px-Human_genetic_isolation_by_distance_in_Kanitz_2018.png