San José, Costa Rica, since 1956

DNA Testing Confirms Tico Blood Well-Mixed

It’s not surprising that Costa Ricans’ DNA, just as that of their neighbors, is made up of a mixture of Spanish, indigenous and African genes. But just how much of each?

Costa Ricans in the Central Valley, where the nation’s capital is located, are 65% European, 30% indigenous and 5% African, according to new DNA research led by Ramiro Barrantes, biology professor at the University of Costa Rica.

A study published recently in PloS Genetics magazine maps out the genes of some 20 different Latin American populations, offering a breakdown that traces back to genetically differentiated populations.

Ticos often refer to themselves as being white, but the biologists researching across the continent were looking beyond skin tone.

Barrantes said the racial breakdown is not entirely new, but the DNA testing confirms, with more advanced technology than before, that the indigenous genes of today’s Ticos are the same as their Amerindian ancestors of 7,000 years before.

But why worry about genetic makeup? “Besides the pleasure of learning more, in recent years we’ve been preoccupied with the makeup of the population – and subpopulations – to pinpoint the relationship between genes and certain hereditary diseases,” the biologist said.

He cited Type 2 diabetes as an example of a known Amerindian gene-related illness.

It’s also important for Costa Ricans to consider their diverse heritage “because they tend to be chauvinistic” because of their insistence on being “white.”

“Sure they’re white, if you take away the Amerindian and African part.”

The study, however, isn’t about race, he said.

“(If you define populations by color) you’re assuming the genes that determine skin color are the ones that predominate or the ones that define. But the color of one’s skin is determined by two or three pairs of genes – the genome has more than 20,000 genes.”



Comments are closed.