(((Davidski)))

[JerryS.]

That is a very intelligent question.

I'm not up to speed on a lot of this so I don't know if that's sarcasm or not. however, even I know that the best population samples for a given region come from that region, not elsewhere. its like somebody scoring some sort of Iberian on a calculator that is actually Sardinian et al. or is it an accepted fact that Sardinian and Corsican people are closer to Spain/Portugal than to say Tuscany Italy?

[JerryS.]

Because they are different calculators for different purposes. Some fit others better, some don’t. Despite being able to achieve low fits/distances, that doesn’t necessarily mean that the end result is accurate for you.

ok, what other purposes other than to use the best possible samples from a specific region/population for each group to obtain the best possible results? there seems to be an obvious disagreement as to what sample population is best for use with certain groups, why is that?

[gixajo]

how could Corsica and Sardinia provide valid sample populations for Spain and Portugal?

Because most of genetic studies are based in comparations among neighbouring (or not) populations.All we do here is to compare one with other, this is how all this works...

3/D.
For admixture f3 analyses, aimed to test for evidence of admixture in a target population, we computed the f3 statistic using all pairs of population from Europe (including Turkey/Greece, Italian peninsula and Iberian peninsula), Caucasus, Middle East, North Africa, and Subsaharan Africa (Table S7). For the outgroup f3 analyses, aimed to estimate the amount of shared drift between a pair of populations, we computed the f3 statistics between a Sardinian (Arzana or Cagliari) and another mainland population, while using the Mbuti individuals as the outgroup. Both f3 and D statistics were calculated using Admixtools v3.0 (ref. 62). Statistical significance was assessed using the default blocked jackknife implementation in Admixtools. Results were displayed geographically using ‘nps’ set of maps available through the OpenStreetMap package in R.

Genomic history of the Sardinian population
Charleston W K Chiang,1,2,3 Joseph H Marcus,4 Carlo Sidore,5,6 Arjun Biddanda,4 Hussein Al-Asadi,7 Magdalena Zoledziewska,5 Maristella Pitzalis,5 Fabio Busonero,5,6 Andrea Maschio,5 Giorgio Pistis,5,6 Maristella Steri,5 Andrea Angius,5 Kirk E Lohmueller,3 Goncalo R Abecasis,6 David Schlessinger,8 Francesco Cucca,5,9 and John Novembre4

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6168346/

[JerryS.]

Because most of genetic studies are based in comparations among neighbouring (or not) populations.All we do here is to compare one with other, this is how all this works...



Genomic history of the Sardinian population
Charleston W K Chiang,1,2,3 Joseph H Marcus,4 Carlo Sidore,5,6 Arjun Biddanda,4 Hussein Al-Asadi,7 Magdalena Zoledziewska,5 Maristella Pitzalis,5 Fabio Busonero,5,6 Andrea Maschio,5 Giorgio Pistis,5,6 Maristella Steri,5 Andrea Angius,5 Kirk E Lohmueller,3 Goncalo R Abecasis,6 David Schlessinger,8 Francesco Cucca,5,9 and John Novembre4

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6168346/

I realize this is an over-simplified view, but wouldn't it be more accurate to get DNA samples from current populations in several locations on Sardinia and then average them out for a "Sardinian" sample?

[digital_noise]

ok, what other purposes other than to use the best possible samples from a specific region/population for each group to obtain the best possible results? there seems to be an obvious disagreement as to what sample population is best for use with certain groups, why is that?

I mean I think you answered your own question. Not everyone fits Eurogenes. For those who don’t, MDLP or one of the others might be a better fit for their background due to the samples used. As for what is best for what group, I don’t know. I think careful, curated use of G25 is the best we’ve got at this point.

[vbnetkhio]

You are a Eurogenes K13 fanatic, nothing new.

if you are interested in the genetics of Central and East Europe and the Balkans, G25 is useless for you.
Davidski is biased against this part of the world, and his tool will be uninformative and in some cases even misleading and wrong for you.
yet he has no problem taking money from East Europeans and Balkanians.

see how for example, he didn't include a single Central Greek in his tool, although a dozen are available.

if i'm interested in Central Greeks, on gedmatch i can check the results of all the academic Central Greeks, plus i can dig through the database and find even more real life central Greeks.

I don't know about the "technical issue" to replace this or that, but I would like to hear what he found objectional about the Central Greeks from Behar et al. 2013?

you can try to ask him on his blog. i wonder how he'll react.

[marco]

if you all believe you can do a better job I’m waiting nobody is forcing you to use the tools or the averaged populations, you can work with the individuals to build a suitable model

[Slavic Italian]

if you are interested in the genetics of Central and East Europe and the Balkans, G25 is useless for you.
Davidski is biased against this part of the world, and his tool will be uninformative and in some cases even misleading and wrong for you.
yet he has no problem taking money from East Europeans and Balkanians.

see how for example, he didn't include a single Central Greek in his tool, although a dozen are available.

if i'm interested in Central Greeks, on gedmatch i can check the results of all the academic Central Greeks, plus i can dig through the database and find even more real life central Greeks.



you can try to ask him on his blog. i wonder how he'll react.

David is an Eastern Euro????? I've noticed a lot of these tests do not register Eastern Euro well and not just his but others who have some association with him. Now as far as hid IBD Analysis. I think it is good to go.

[vbnetkhio]

David is an Eastern Euro????? I've noticed a lot of these tests do not register Eastern Euro well and not just his but others who have some association with him. Now as far as hid IBD Analysis. I think it is good to go.

i think he's an Eastern Euro wishing to be a Western one, and sucking up to them.

the only proper averages he made in G25 are for NW Euros. also, his Yamnaya/WHG/EEF model is NW-Euro centric, and doesn't even work well for his own people, the Poles.

[Leto]

Davidski's Russian, East Slavic averages from G25 are okay. I think they are academic.