Subjectivity in the grouping of Autosomal markers

[Galaico]

The following example shows how subjective and ridiculous is the grouping of Autosomal markers:

Autosomal markers are subjectively linked to a specific group (e.g. Finno-Ugrian, NW European, etc.).



So I, subjectively assume that all European genes found in Andalusia (~55%) are of Iberian origin. Why not? Andalusia has equally Paleo-Iberian origin and Neolithic influence from Arabia, North Africa, etc.

So using the very same information than in the previous chart, I can build up the following chart, that though in a different way, will represent the same information as the previous graph.

So in my hypothesis all European genes found in Andalusia are really Iberian, so:

55% Iberian = 9% Finno-Ugrian + 25% NW European + 7% E. European + 14% Mediterranean

What simplifies to:

100% Iberian = 16% Finno-Ugrian + 45% NW European + 13% E. European + 25% Mediterranean



It is simple Maths: substitution. Same results but different point of view.

[Polak]

I certainly hope you're not comparing these cheap commercial hobby tests with the stuff used in academic reports (ie. thousands of slow-mutating genome wide SNP markers)?

You really need to understand that the only way to obtain the precise fraction of ancestry is through genomic studies. Single marker systems are subject to drift and Y-STRs mutate too fast anyway.

Here's an exmple of a detailed genomic test. If you have seen any useful criticism of this test and the methodology used then please post it.

PLoS Genetics - European Population Substructure: Clustering of Northern and Southern Populations

From now on let's refer to such tests at genome wide SNP tests, and not Autosomal tests, because you seem to be confusing simple hobby and paternity tests with the real stuff.

[Polak]

There you go sunshine. Forget the Autosomal tests, this is really what we're talking about...

http://cropandsoil.oregonstate.edu/c...ture_Knapp.pdf

[Menydh]

Originally Posted by Polak

There you go sunshine. Forget the Autosomal tests, this is really what we're talking about...

http://cropandsoil.oregonstate.edu/classes/css630/!SNP_Lecture_Knapp.pdf

• Most SNPs are bi-allelic and thus less informative than multi-allelic markers (e.g., RFLPs and SSRs). This weakness can be offset by SNP tiling, but development costs must be factored into the equation.
• SNP assays can only be performed on total DNA in species with small genomes (e.g., yeast) (Winzeler et al. 1999). DNA must be amplified from individual loci in species with large genomes (e.g., humans and most plants and animals). This is a bottleneck in ultra-high throughput and massively parallel SNP genotyping.
• This weakness can be offset by multiplexing; however, developing multiplexes is costly and technically demanding, and not all loci multiplex. The multiplexes developed by Affymetrix for the human SNP genotyping chip (www.affymetrix.com), for example, excluded half of the SNP loci tested (i.e., half could not be multiplexed).