Love may be blind, but DNA is mysterious

SAN FRANCISCO, Dec. 4 (UPI) -- People mysteriously marry those with similar ancestry, U.S. researchers say.

Study leader Neil Risch of the University of California, San Francisco, says mysteriously, the correlation of physical characteristics linked to ancestry -- such as skin pigment, hair texture, or eye color -- are actually below what is required to fully explain the phenomenon. Also, geography or socioeconomic status could not explain the ancestral influence on romance.

The study, published in Genome Biology, is based on information from colleague Esteban Gonzalez Burchard's The Genetics of Asthma in Latino Americans.

"Latin America provides a unique opportunity to study population structure and non-random mating, due to the historical confluence of European, Native American and African racial groups over the past five centuries," Risch says in a statement.

Specifically, Risch, Burchard and colleagues find Mexicans mate according to proportions of Native American to European ancestry, while Puerto Ricans are more likely to settle down with someone carrying a similar mix of African and European genes.

Not only are there similar ancestry patterns between spouses, an imprint of many non-random associations of genes between original ancestral populations is found within the genomic architecture within each individual.