Scientists have long believed that modern humans, or Homo sapiens,

originated in Africa and then migrated to other parts of the world. 

However, a new study published in the journal Nature suggests that 

human origins in Africa may be more complex than previously thought. 

The study, led by researchers from McGill University and the 

University of California, Davis, analyzed the genomes of 290 living people 

from four geographically and genetically diverse African groups. 

The researchers found that these groups were not all equally related to each other.  

Instead, they found evidence of multiple waves of migration and 

intermixing between different populations of early humans in Africa.