# DNA test for race? **URL:** \ **Category:** Great Debates\ **Created:** [June 5, 2003, 2:37am UTC](https://boards.straightdope.com/t/dna-test-for-race/179753 "2003-06-05T02:37:40Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![bdgr](https://avatars.discourse-cdn.com/v4/letter/b/a87d85/32.png) [@bdgr](https://boards.straightdope.com/u/bdgr)\ **Post date:** [June 5, 2003, 2:37am UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/1 "2003-06-05T02:37:40Z")
On the news, they anounced that in the hunt for the serial killer in La, they determined that the killer was black due to DNA tests. Since there is no biological basis for “race”, then how did they determine the race of the suspect? ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [June 5, 2003, 2:51am UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/2 "2003-06-05T02:51:37Z")
One possibility is that killer carries a rare peice of genetic material found only in black people. This doesn’t equate to a test for race, it equates to a test for a family. If you know that family’s race then you know the perpetrators race. Of course it’s not 100% even then. If a black person has a child with a white person, the child can be white and still carry the marker. ---
**Author:** ![scotandrsn](https://avatars.discourse-cdn.com/v4/letter/s/a4c791/32.png) [@scotandrsn](https://boards.straightdope.com/u/scotandrsn)\ **Post date:** [June 5, 2003, 6:35am UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/3 "2003-06-05T06:35:44Z")
Um… they know from the DNA how much skin melanin is coded for…? Yah, maybe…? ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [June 5, 2003, 6:46am UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/4 "2003-06-05T06:46:45Z")
Unless things have advanced a lot recently we aren’t even close to being able to do that. ---
**Author:** ![OliverH](https://avatars.discourse-cdn.com/v4/letter/o/278dde/32.png) [@OliverH](https://boards.straightdope.com/u/OliverH)\ **Post date:** [June 5, 2003, 6:50am UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/5 "2003-06-05T06:50:17Z")
> [@](#): > > \*Originally posted by bdgr \* > \*\*On the news, they anounced that in the hunt for the serial killer in La, they determined that the killer was black due to DNA tests. Since there is no biological basis for “race”, then how did they determine the race of the suspect? \*\* Careful. There is no biological basis to speak of ‘race’ in the biological sense. That ‘race’ has a well-defined meaning that is quite different than ‘ethnic groups’. There is no biological basis because members of a given ethnic group differ a lot in their genes, and can actually be genetically more similar to a member of a different ethnic group than to a member of their own. In order for them to constitute a biological ‘race’, all black people, for example, would have to be genetically more similar to each other than to caucasian people, or asian people. That, however, leaves the existence of certain genetic traits nonwithstanding. There can still be common factors among the members of a given ethnic group. One candidate that has long been postulated is the frequency of certain non-coding repetitive sequences of DNA in front of certain genes, which were thought to possibly play a role in gene expression and with it the individual susceptibility of certain ethnic groups to certain diseases (such as sequences close to the androgen receptor gene being a factor in ethnic susceptibility to prostate cancer). However, that is an issue that is extremely poorly understood and highly disputed among parts of the scientific community. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [June 5, 2003, 6:50am UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/6 "2003-06-05T06:50:33Z")
Blake is almost right, but Scott is wrong. There are genetic markers that can indicate what geographic region your ancestors came from. To the extent that “geographic region” can correlate to “race”, then forensics can determine the “race” of an individual from his or her DNA. This obviously runs into problems with people of mixed racial (or mixed geogarphic) heritage. And depending how the testing is done, one can look at the maternal line and/or the paternal line. The maternal line is presevered in the mtDNA (mitochondrial DNA) that is only inherited from the mother. For males, there are markers on the Y chromosome that can indicate geographic origin of the paternal line, since all the genes (and markers) on the Y chromosome are inherited from the father. For women, tracing genetic markers thru the paternal line is not currently possible (as you know, women have no Y chromosome). So, for a male, it might be possible to determine that the person had a “white” (read: European) mother and Black (read: African) father, for example. This is somewhat of a simplification, but pretty much covers it. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [June 5, 2003, 6:54am UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/7 "2003-06-05T06:54:11Z")
Check out [this site](http://www.oxfordancestors.com/) if you want to read more about this. They even offer a service to trace your genetic ancestory (for a fee, of course!). **Note: I’m not recommending or endorsing this service. Just noting that they have some good background info on genetic testing.** ---
**Author:** ![bdgr](https://avatars.discourse-cdn.com/v4/letter/b/a87d85/32.png) [@bdgr](https://boards.straightdope.com/u/bdgr)\ **Post date:** [June 5, 2003, 7:00am UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/8 "2003-06-05T07:00:43Z")
> [@](#): > > \*Originally posted by John Mace \* > \*\*Blake is almost right, but Scott is wrong. > > There are genetic markers that can indicate what geographic region your ancestors came from. To the extent that “geographic region” can correlate to “race”, then forensics can determine the “race” of an individual from his or her DNA. > > This obviously runs into problems with people of mixed racial (or mixed geogarphic) heritage. > > And depending how the testing is done, one can look at the maternal line and/or the paternal line. The maternal line is presevered in the mtDNA (mitochondrial DNA) that is only inherited from the mother. For males, there are markers on the Y chromosome that can indicate geographic origin of the paternal line, since all the genes (and markers) on the Y chromosome are inherited from the father. For women, tracing genetic markers thru the paternal line is not currently possible (as you know, women have no Y chromosome). > > So, for a male, it might be possible to determine that the person had a “white” (read: European) mother and Black (read: African) father, for example. > > This is somewhat of a simplification, but pretty much covers it. \*\* Thats what I suspected, that they could guess pretty well what population their ancestors came from, and therefore have a reasonable certainty of what their skin color is/was from the geographic location. When they started throwing around the word race and DNA in the same breath, I started wondering if I missed something. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [June 5, 2003, 7:38am UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/9 "2003-06-05T07:38:10Z")
> [@](#): > > This obviously runs into problems with people of mixed racial (or mixed geogarphic) heritage. Given the evidence we have of widesspread outcrossing throughout the last 40, 000 years at least, wouldn’t it only present probabilities at best? I’m wondering why an Ethiopian couldn’t carry an Nordic marker due to some hanky panky by Alexanders troops for example? Or why a German couldn’t be carrying Korean markers thanks to Gehnegis Kahn raping his great, great, great, great grandmother? Surely there must be some inherent error due to these events. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [June 5, 2003, 1:58pm UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/10 "2003-06-05T13:58:47Z")
> [@](#): > > \*Originally posted by Blake \* > \*\*Given the evidence we have of widesspread outcrossing throughout the last 40, 000 years at least, wouldn’t it only present probabilities at best? > > I’m wondering why an Ethiopian couldn’t carry an Nordic marker due to some hanky panky by Alexanders troops for example? Or why a German couldn’t be carrying Korean markers thanks to Gehnegis Kahn raping his great, great, great, great grandmother? > > Surely there must be some inherent error due to these events. \*\* You’re right-- it’ll always be a “probability”. But there are quite a few known markers that are used, so it’s not like they’re just looking for one and might get fooled. If the police had been more technically accurate, they might have said something like: “the suspect has 8 of the 10 know markers that indicate recent African ancestory so we are highly confident we are searching for a Black man.” Not so easy to report, I guess, as saying “DNA evidence shows the suspect is Black.” One would expect that almost all African-Americans would have some European markers. Not from 40,000 or 2,000 years ago, but aquired in the last 400 years. ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [June 5, 2003, 3:28pm UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/11 "2003-06-05T15:28:32Z")
In _Science_ magazine, last December (20 December, 2002, Vol 208), they published a study by Noah Rosenberg, _et al_, “Genetic Structure of Human Populations.” In it they described using a constellation of loci to group 1056 individuals from 52 known populations. They found that, using statistical analyses, they could identify five major geographical locations of origin. (Within those regions, individuals could exist who shared no similar markers, but they would all share certain different markers that were statistically associated with the same region.) If the forensic pathologists in the Louisiana case used that (or similar) methods, they could very likely have identified Africa as a point of origin. Since the number of Pygmy and Khoi-San individuals in Louisiana are vanishingly small, a general description of “black” would be a legitimate conclusion to draw. ---
**Author:** ![bdgr](https://avatars.discourse-cdn.com/v4/letter/b/a87d85/32.png) [@bdgr](https://boards.straightdope.com/u/bdgr)\ **Post date:** [June 5, 2003, 8:46pm UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/12 "2003-06-05T20:46:11Z")
I emailed fox and got this response > [@](#): > > \*\* > You’re right. It appears we may have oversimplified > matters in our brief story, even if the thrust of the > story was correct. > > Thanks for writing, and thanks for watching FOX \*\* ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [June 5, 2003, 9:05pm UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/13 "2003-06-05T21:05:02Z")
DBGR: Good job! Care to post the e-mail you sent? ---
**Author:** ![bdgr](https://avatars.discourse-cdn.com/v4/letter/b/a87d85/32.png) [@bdgr](https://boards.straightdope.com/u/bdgr)\ **Post date:** [June 5, 2003, 9:18pm UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/14 "2003-06-05T21:18:57Z")
In your news broadcast you stated that DNA was used to identify the race of a suspected serial killer. This is technically not correct as race has no biological meaning, therefore cant be identified by DNA (two people sharing physical characteristics such as skin cooler likely share no genetic history). However, DNA can be used to identify a geographic location of ancestors, which is likely what the police used to make an educated guess a the race of the suspect. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [June 5, 2003, 9:34pm UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/15 "2003-06-05T21:34:57Z")
Bdgr, making the world a more educated place one issue at a time! ---
**Author:** ![bdgr](https://avatars.discourse-cdn.com/v4/letter/b/a87d85/32.png) [@bdgr](https://boards.straightdope.com/u/bdgr)\ **Post date:** [June 5, 2003, 9:46pm UTC](https://boards.straightdope.com/t/dna-test-for-race/179753/16 "2003-06-05T21:46:36Z")
lol