I don't mean to be difficult or offensive in any way, but I really don't understand your point here...
23andme uses ALL the publicly available autosomal research data sets for its analysis; that means it uses the HGDP data set, but it uses many others as well, including the many other Tuscan data sets, as just one example. In addition, it uses the data of all of its members with four grandparents from Italy, by region. So, it has the data of people with ancestry from southern Italy, Liguria, the Veneto and on and on as part of its data base.
The fact that it is continually adding to its data base as more people submit their samples is the reason that the results keep changing...as more people add their data, the results become more and more precise. Of course, lots of data can only do so much...the algorithm has to be good as well. If you haven't yet looked at it, you should read the White Paper where the 23andme scientists explain it...it's very impressive I think...no one else is doing anything like it...
As to your comment about Gedmatch, I also find that confusing. Gedmatch has provided versions of calculators created by a number of hobbyists, including Dienekes. The hobbyists differ in the number of publicly available data sets that they use. To my knowledge, Dienekes is the only one who uses all of the publicly available autosomal data sets for Italians, and, in addition, like 23andme, he has access to the autosomal data of Italians from areas that have not been sampled in research studies. Then, of course, it all depends on whether you trust the objectivity and the competence of these analysts. I don't trust some of their results at all.
In terms of the other tools available at gedmatch, yes, people can compare themselves to other people who have made their data available, etc. However, whether most people who are using these tools have any idea what they're doing, or how to interpret the results...well, let's say that I am highly skeptical, and leave it at that.
Pardon? , yes it uses only those stated, it does not use ftdna, while gedmatch does, it does not use ancestry, which gedmatch does. it uses only what it states.
what this below mean from 23andme ancestry composition?
Ancestry Composition tells you what percent of your DNA comes from each of 31 populations worldwide.
The analysis includes DNA you received from all of your ancestors, on both sides of your family.
The results reflect where your ancestors lived 500 years ago, before ocean-crossing ships and airplanes came on the scene.
Italian
The peninsula of Italy is home to a genetic legacy not only of the Roman Empire,
but also of groups from both northern Europe and the eastern Mediterranean
that occupied Italy at various points in its history.
hide details
French & German
Connected to the British Isles, Scandinavia, southern Europe and eastern Europe,
France and Germany have seen myriad peoples come and go over the last ten thousand years.
Genetically and geographically the French and Germans are at the heart of Europe.
Population | Source | Sample Size |
---|
Germany | 23andMe | 367 |
Netherlands | 23andMe | 207 |
France | 23andMe | 200 |
Switzerland | 23andMe | 87 |
Belgium | 23andMe | 80 |
Austria | 23andMe | 54 |
France | HGDP | 29 |
hide details
I agree it adds to its data , but uses only these numbers above as listed on its site.....yes it adds numbers , like switzerland went from 77 in November 2013 to 87 now
Where does it say it uses more that what is noted on its site?
yes Gedmatch uses admixture settings created by dodecad, eurogenes, MdLP etc ( dodecad only had 5 north-italian samples ) and adds the numbers from every genetic testing company of the people that join Gedmatch. it will add 23andme, ftdna, ancestry , genomes etc and then uses their formula from the selected creator,
example, say you choose Eurogenes K13 ........so while eurogenes might have 50 north-italian in their data for their initial test, gedmatch will add all the other north-italian data from every other testing company into the mix and use the eurogenes formula to give you a result.............so you answer will not be from 50 NI, but many many more.
Using far more people from different testing companies, which is why, gedmatch gives me 5 times more matches , than ftdna and 23andme combined. 5 times more matches means more people's data is used to determine the final result
BTW, dienekes which is dodecad uses only 5 north-italian samples as i tried to enter my data numbers ( and I qualify) and was told its closed and is set as 5 in number