| DrARL | 01-30-2011 08:13 PM |
How heredity tests work
I'm not a dog breeder. I'm a mutt owner trying to find out whether the test is worth doing just for fun. I also have a PhD in molecular genetics, and know the fairly simple reason these tests can't be used to identify purebred animals:
Ancestry tests (including human ones) do not sequence the entire genome, nor do they test for phenotypic traits. Genes for things like hair color are too similar, even in differently colored animals, to be used in this type of test. Test makers identify snippets of the more variable "non-coding" DNA that are specific to a breed. The more snippets of DNA specific for a given breed are included in the test, the more accurately the test will identify the proportion of the ancestry attributable to that breed. However, these pieces of DNA are a tiny fraction of the entire genome, so the test could never "prove" that a dog was a purebred. It could only identify a single breed as the source of the snippets that were tested.
Why couldn't the test makers explain this? | 