since my affinity runs so deep I wonder if I may actually have Irish ancestry? Would anyone like to comment on this? I have heard that the Celts sojourned into Slavic lands many centuries ago. Perhaps that's the connection.
possible but it would be negligible, european genes differ relatively dramatically (but due to breeding with females of common genetic type everyone from Europe looks white) .
In ancient times Galicia was Celtic, indeed that is where the name derives from (along with Galicia in Spain and Galatia in Turkey) the populations were largely dispersed with the "arrival" of the Slavs.
Every person has a gene whats called a mtdna haplogroup, which is a gene directly inherited from ones mother (who gets it from her mother, and her mother gets it from her mother etc)
Those also a similar gene that one gets from the father, and he from his father etc unique to males called the y-haplogroup. There is a clear difference between Western Europeans and Eastern Europeans in this regard.
Now compare the (as I call it) "Celtic" y-haplogroup gene R1b, carried by about 80-95% of Irish, British, French, basques (who unrelated note are closest relatives to ancient Britons which is why some british people have dark complexion), and northern Spaniards http://4.bp.blogspot.com/_tR4bYTcAq...hXfgPcpCk/s1600/r1b-dna-distribution.jpg
to a map of historic habitation of the celts http://img98.imageshack.us/img98/5894/keltearlymap9jw.gif
as you can see they match
Slavs on the other hand are later arrivals from India to Europe than Western Europeans, emerging in written records in around 500AD (though certainly they existed before, probably coming from south asia via central asia between 6,000-18,000 years ago) from the Scythians whom themselves emerged from the mysterious Kurgan mound builders. One can examine the pagan art in ancient Iran and the steppes of south Siberia/Kazakhstan (Kazakhstan was before turkic tribes Iranian Scythians/Kurgan mound builder territory) and find identical matched to pagan Slavic art
now look at the Slavic R1a gene in Europe (if dosent link copy and paste to your search bar)
here is a world map of the R1a genehttp://rpmedia.ask.com/ts?u=/wikipe...ibution.png/300px-R1a1a_distribution.png
R1a is much newer than R1b, R1b is ancient enough that unlike R1a it has lots of mutations. This allows scientists to match sometimes the exact village your paternal ancestor came from. Not so with R1a, using a basic test I, being R1a with Slavic ancestry, will match exactly with a west bengal brahmin (thats eastern border of india) where as I would not come close period to an Irishman.
oh back to your question, hehe, about 25% of people in galacia are R1b, so you may take comfort that your direct paternal great-grandfather x80 may
have been a celt.