"We started with 22 landmarks on the faces that could be accurately located in all the images," said Shriver.
These landmarks might be the tip of the nose, the tip of the chin, the outer corner of the eye or other repeatable locations. They then recorded the distances between all the points in all directions, so they had a distance map of each of the faces.
From their DNA profiles, Shriver could determine the admixture percentages of each individual, how much of their genetic make up came from each group. He could then compare the genetically determined admixture to the facial feature differences and determine the relative differences from the parental populations.
"This type of study, done on admixed populations shows that each person is a composite of their ancestors and that the range of facial features is a continuum," says Shriver.
Shriver found that there was a very strong statistical correlation between the amounts of admixture and the facial traits.
"We chose to look at African Americans because they were a large enough and available admixed population," said Shriver. "We are trying to solidify our understanding of the origins of humans and the evolutionary processes. Looking at admixed populations shows us the influence genes have and how they relate to physical features."
|Contact: A'ndrea Elyse Messer|