Researchers at Potsdam University have developed a test they claim can identify a person's ethnicity based on a blood sample. The researchers have developed a bioassay based on the identication of two biomarkers which they claim can differentiate between persons of "caucasion of african american ethnicity".
This test was designed for forensic application, the distinguish blood samples found at crime scenes.
I have mixed feelings about such a test. In the post-conviction context I can see a signficant benefit. In that situation you are trying to exclude someone - namely the person who was convicted. If the defendant is caucasion and the blood is from an African American, then that is an important fact.
On the other hand, in trial cases there could be a tremendous potential for misuse. Jurors seldom grasp statistics and probabilities. If the blood comes from an African American an the defendant is African American, they interpret that as meaning the defendant is guilty.
I also wonder as a practical matter how this can be used. If you have blood sample, you should be able to perform a DNA test, which would me more discriminating. Also, there is seldom a dispute about the ethnicity of a perpetrator - only the identification. Finally (I'm sure there are more), how does the test distinquish persons of mixed races?
Perhaps the use of this is as a quick investigative tool that can be done at the scene so police can narrow the suspect pool. If it's used for more than that, I see far too many problems to permit it's use in deciding whether we should take away soomeone's freedom.