To determine which theory is best supported by the map, it would be helpful to know what the map depicts. However, if the map indicates migration routes or land formations (like the Bering Land Bridge), the best-supported theory would likely be:
"Early humans migrated from Asia to North America over a land bridge."
This is based on the widely accepted theory that early humans crossed from Asia to North America via a land bridge that existed during the last Ice Age. If the map supports this migration route specifically, this would be the most appropriate choice.