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It's called the Great Migration, the journey of some 6 million African Americans from the rural south to northern and

western cities between 1910 and 1970. The cultural impact of the Great

Migration has been well documented, but researchers have also started to look at its genetic

implications. The most recent study finds that the migration had a significant

effect on genomic diversity across the nation. That work is in the journal plus genetics. To estimate

patterns of ancestry, researchers analyzed genetic data from nearly 4,000

African Americans who had participated in three medical studies.

Their findings confirmed historical records.

Genetic evidence showed that female slaves often gave birth to children fathered by white slave owners.

The genetic analysis found that 82.1% of the

average African Americans ancestors came from Africa, while 16.7% were Europeans and 1.2% were Native American.

The team also could date when particular genes entered the mix.

Native American genes were introduced into the typical African Americanome in the

early 1600s.

Genes from Europeans were for the most part introduced in the decades before

and during the Civil War.

Researchers also found those still living in the southern United States have a greater percentage of African

ancestry than those in the north or west.

And European Americans who now live in the south or more genetically similar to African Americans in the

north and west than they are to African Americans currently living in the South because

blacks with a greater percentage of European ancestry were more likely to move, especially early in the migration's history.

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