As I mentioned in my previous post, the genotype data provided by companies such as 23andMe and deCODEme allow us to build ancestry assessment tools that use published genotype data from scientific studies.
I have built a simple classifier tool based on the panel of 300 markers of Price et al. (2008), which uses the frequency data supplied in this paper to assess the probability that an individual belongs to the "Northwest European", "Southeast European", or "Ashkenazi Jewish" categories.
The input is genotype values for a number of markers (e.g., the 169/192 markers in common between the deCODEme and 23andMe results) for an individual, and the output is a set of three probabilities for belonging to any of the three groups, summing up to 1.
Using the Greg and Lilly Mendel data that you can download from 23andMe, I came up with the following probabilities (NWE,SEE,AJ):
Greg: 0.89, 0.11, 0
Lilly: 1, 0, 0
(corrected June 15)
23andMe lists the similarity of these individuals to "Northern Europeans","Southern Europeans", and "Near Easterners" as:
Greg: 67.84, 67.74, 67.15
Lilly: 67.85, 67.72, 67.11
So, at least for these two individuals the results of my calculator appear to be analogous to those reported by 23andMe, with Lilly seeming more "Northern" than her husband.
PS: Unfortunately my calculator cannot be released at present, as it's not a standalone program but rather relies on a bunch of different tools with minimum development.