Modern humans originated on the continent of Africa more than 300,000 years ago, and subsequent generations migrated across the land, with groups intermarrying or splitting apart. Sometime around 80,000 years ago, a small number of descendants left the continent and radiated around the globe, taking with them just a subset of the genes and genetic variation that their ancestors had developed. Yet genetic studies are now dominated by that subset, according to a new article in Cell. As of last year, 78 percent of the people included in the most prominent form of genomic research—genome-wide association studies (GWAS)—were of European ancestry. But worldwide, Europeans and their descendents make up just 12 percent of the population. According to the researchers, heavily biased genetic databases could—and do—lead scientists and doctors to diagnose conditions or prescribe treatments that might be relevant to people with European genes, but not for people from other racial backgrounds. “If we don’t include ethnically diverse populations, we are potentially going to be exacerbating health inequalities,” said Sarah Tishkoff, study coauthor and a human geneticist at the University of Pennsylvania. Which statement from the passage establishes the author's claim?

Question

A. "Yet genetic studies are now dominated by that subset, according to a new article in Cell."
B. "Sometime around 80,000 years ago, a small number of descendants left the continent and radiated around the globe, taking with them just a subset of the genes and genetic variation that their ancestors had developed."
C. "According to the researchers, heavily biased genetic databases could—and do—lead scientists and doctors to diagnose conditions or prescribe treatments that might be relevant to people with European genes, but not for people from other racial backgrounds."
D. "As of last year, 78 percent of the people included in the most prominent form of genomic research—genome-wide association studies (GWAS)—were of European ancestry."

Answer 1

The statement that best establishes the author's claim is C: "According to the researchers, heavily biased genetic databases could—and do—lead scientists and doctors to diagnose conditions or prescribe treatments that might be relevant to people with European genes, but not for people from other racial backgrounds."

This statement directly addresses the consequences of the biased genetic databases, supported by the dominance of European ancestry in genetic studies, which ties to the claim that not including ethnically diverse populations can exacerbate health inequalities.