Tuesday, November 28, 2017

Clarifying the Forensics of Anatomy and Race

I had a great talk with an anatomy teacher and another science teacher.  I also spoke with a science department chair from another high ranking high school.  They helped clarify that yes forensic anatomy can be used to help identify a person but that you cannot biologically separate people into distinct races.  Here is what I found:

 There are 2 very important caveats to understanding the forensic anatomy lab.  First, forensic science is not determinative - in other words it is not able to distinctly place people into a racial group.  It is more of an educated guess or a probability.  Secondly, the data must be compared to the types of people in the United States.  This is not a categorical definition that applies to people around the world.  It only applies to people in the U.S. because of our heritage and our terminology, which are social creations.

The forensics analysis is really analyzing different gene pools of certain traits for groups of people who are in the U.S.  Using forensic evidence, one can cross reference the likelihoods of different characteristics that a person might have.  Then the forensic anthropologist correlates those characteristics to a region of the world.  Finally, this region can be compared to how Americans define race.

For example, look at the genetic traits that are on the Race Power of Illusion website (see the maps below or click on the link then on physical appearance for more info).  The maps show that certain traits (such as head size or nose width) are more likely in different populations of people.  A forensic anthropologist might try to pinpoint what geographic region of the world has the highest  concentration of the overlapping traits.  In other words, he might put layers of evidence that do not line up with "race" on top of each other in order to determine the most likely location of genetic ancestry of the person.  Then using this approximate location, the forensic anthropologist might take that geographic region and say, "What would someone from this region be called in the U.S.?"  From that he might say black or white or Asian, but that doesn't mean that all people in that group would contain that combinations of traits.

Here are just two traits to correlate:























In the above maps, imagine forensic evidence that finds a large skull (see the head size map directly above).  Where might that person be from? Scotland, West Africa, or Southern India.

Now, look at the top map and imagine that the evidence also showed that the skull had a broad flat nose (92-97).   Where is the probability highest that  this skull be from?  Southern and Western Africa or Australia.

A forensic anthropologist might say then that the probability is most high that the person is of West African origin because that is where the two data points correlate.  Then, the anthropologists might say that in the United States, a person from West Africa is likely called "black or African American".  Note that this is only a probability and only works because of the population of West Africans who were forced to the U.S. in slavery.  But if the evidence revealed a medium head size and a long narrow nose (66.9-71.9) the person might be from Scandinavia, Eastern Russia or the Horn of Africa.  These places all have these genetic traits correlating in higher probability.  Obviously this would be a much more difficult task.  These traits help to point to a specific region of the world where there is a high probability that an individual's ancestors came from, but it doesn't define biologically what "race" is.

I hope this helps clarify the anatomy lesson for you and reconcile it with the idea that people cannot be grouped biologically into "races".  However, it also validates the idea that forensics helps to identify the probability that a person is from a certain gene pool/geographic region.

Tomorrow we will explore how that gene pool gets labelled as a "race".

For more info, a number of experts answer the following question:
If race isn't biological, how do forensics investigators determine a person's race using their bones or DNA?

To see their answers click here.

To see more FAQs click here.

To read about the experts, click here. 

No comments:

Post a Comment