by Tracy R. Walsh
We’re one step closer to it:
Sometime in the future, technicians will go over the scene of the crime. They’ll uncover some DNA evidence and take it to the lab. And when the cops need to get a picture of the suspect, they won’t have to ask eyewitnesses to give descriptions to a sketch artist – they’ll just ask the technicians to get a mugshot from the DNA.
That, at least, is the potential of new research being published [yesterday] in PLOS Genetics. In that paper, a team of scientists describe how they were able to produce crude 3D models of faces extrapolated from a person’s DNA. “We show that facial variation with regard to sex, ancestry, and genes can be systematically studied with our methods, allowing us to lay the foundation for predictive modeling of faces,” the researchers wrote in their paper. “Such predictive modeling could be forensically useful; for example, DNA left at crime scenes could be tested and faces predicted in order to help to narrow the pool of potential suspects.”
Sara Reardon explains:
[Mark] Shriver and his colleagues took high-resolution images of the faces of 592 people of mixed European and West African ancestry living in the United States, Brazil and Cape Verde. They used these images to create 3D models, laying a grid of more than 7,000 data points on the surface of the digital face and determining by how much particular points on a given face varied from the average: whether the nose was flatter, for instance, or the cheekbones wider. They had volunteers rate the faces on a scale of masculinity and femininity, as well as on perceived ethnicity.
Next, the authors compared the volunteers’ genomes to identify points at which the DNA differed by a single base, called a single nucleotide polymorphism (SNP). … Then, taking into account the person’s sex and ancestry, they calculated the statistical likelihood that a given SNP was involved in determining a particular facial feature. This pinpointed 24 SNPs across 20 genes that were significantly associated with facial shape. A computer program the team developed using the data can turn a DNA sequence from an unknown individual into a predictive 3D facial model.
Peter Aldhous notes the research opens up “the intriguing possibility of producing facial reconstructions of extinct human relatives”:
Even for Neanderthals, where there are numerous fossil skulls, palaeoanthropologists have little idea about the soft tissues of the face. “We don’t know how far out their noses extended,” says Shriver. This means that artists’ impressions of what the species looked like are partly guesswork. Shriver hopes that there will be enough overlap between the Neanderthal and modern human genomes for variants that influence face shape to start filling in such gaps.
(Image via PLOS Genetics)
The Dish 