How did the current theories address how New World primates reached America?

The correct response highlights a significant theory regarding the dispersal of New World primates to the Americas. This theory suggests that these primates migrated across an extinct land bridge, specifically the land connection that once existed between Asia and North America. This land bridge, known as Beringia, facilitated the movement of many species during periods of lower sea levels, allowing for migration to occur.

In the case of New World primates, the ancestors likely traveled from Africa to North America via a combination of overland routes and possible subsequent adaptations to reach South America. However, the major advancements in understanding how these primates arrived in the Americas emphasize the role of a land bridge, which was crucial in connecting the continents at various points in history.

This migration theory is further supported by fossil evidence and genetic studies that trace the origins and dispersal of these primates, linking them back to their evolutionary relatives found in Africa. The idea of independent evolution or adaptation to environmental changes does not adequately explain the geographic and temporal dispersion observed in the fossil record. Meanwhile, marine transport from Africa is not supported by prevailing data, as primates are not known to have the capabilities for crossing large oceanic distances in such a way.