It is fact that genetics from one Slavic ethos (nation) to another giving variable results on the first place thanks to fact that Slavs are ethnic grupation positioned on vast geographical territory in different micro climatic environment. To say, Slavs are ethos positioned on the inter-continental level.
But also, there are traces in genes which suggest that Balkan represent oldest core of Slavic kind, from where Slavic (Proto Slavic) population dispersed following Danube River and further.
On the article/link (by Hindu Institute of Learning) we can read about genetic mutations which are affected by changes in environment (longer population is positioned in place, higher % of Eu7). Eu7 genetic mutation is of highes percent on Balkan. Other Slavic populations (West, East, North) has lower percent (in circles around Balkan) of Eu7 markers due to fact that later was positioned on their territory, coming from Balkan. But, even so those Slavic populations are autochthonous populations on their today's territories thanks to fact that their `journey` was finished some 10.000 BC (minimum) years ago, as genetic result suggest. That about direct conclusions from genetic results.
Indirectly, we can conclude that Serbians and Croats preserved their genetics, no matter fact that they were often conquered by non-Slavs, even non-Whites. In other words, a genetic samples taken particularly from Serbs doesn't show genetic traces (changes) as result of mixing with eventually later arriving conquerors/invaders.
According to the authors this phenomenon is explained by "...contribution to the Y chromosomes of peoples who settled in the Balkan region before the Slavic expansion to the genetic heritage of Southern Slavs..."
and yes Serbs were conquered and had to serve ... and they were tradable good.
Luk giving wrong interpretation of presented genetic results. There are no traces of changes in genes taken as samples from Serbian population, at least not in last 20.000-25.000 years, as genetis foundings suggest.
In Luk`s article of Wikipedia we only see proof that Western Balkan (today`s Serbia) represent oldest Slavic core.
But also, Wiki`s article say `before the Slavic expansion `. Here we must say that Slavic expansion didn`t happened late in 600-700 AD (Wiki`s article suggest that Slavs arrived late and assimilated older population) but much before BC. Slavs are that autohtonmous population of Balkan and article of Wikipedia trying to avoid to underline that and, Serbian/South Slavic genetic results are different from other Slavic genetic results on the first place in percent of Eu7 genetic markers, which are highest thanks to long and continual existance in same enviroment (Balkan), from where all Slavs dispersed.RELATIONSHIP BETWEEN INDIAN POPULATIONS AND EUROPEANSJoseph Skulj, Jagdish C. Sharda, Snejina Sonina, Petr Jandacek
Hindu Institute of Learning
M170 Lineage-Distribution and Age:
Semino proposes that M170 originated in Europe in descendants of men that arrived from the Middle East 20,000 to 25,000 years ago,... After climatic improvement, this culture spread north and east (Semino et al. 2000).
Semino proposes that the polymorphism M170 from which haplotype Eu7 is derived represents another putative Paleolithic mutation whose age has been estimated to be ~22,000 years. The mutation is most frequent in central Eastern Europe, at 45 % in Croats and 49% in Yugoslavs (Rosser et al. 2000) and also occurs in the Basques that have accumulated a subsequent mutation (M26) that distinguishes Eu8 (Semino et al.2000). It is also present on the Indian sub-continent; Pathan and Sindhi in Pakistan show a frequency of 16% and 9% (Qamar et al. 2002).
NOTE: `Yugoslavs` represent population of Serbia (Human Genome experiment occurred when name of Yugoslavia officially still was in use but in that time republics of Yugoslavia were just Serbia and Montenegro. Genetic samples were taken in Serbia.)