Fact that they speak Slavic language is because of Slavic conquering in 6th century (invited by Byzantium to fight Avars, according to Slavic migration theory), but that does not mean they magically changed into Slavs like those in Poland, Belarus, Ukraine or Slovakia, their blood and ancient heritage still remained with them.
well said. Its very important to underline that ethnic categories are not related to genetics. Genes are not part of national characteristics cause not all member of the same nation share genetic factors. Some nations are more homogeneous than other but that is relativity. What I am trying to say is that if we discuss about whether Macedonians are Slavs or ancient Macedonians , we cant use blood as evidence but ethnic characteristics like language, culture that was made on that language, tradition etc. Among modern Macedonians those characteristics are Slavic and that is it. If we say that because of blood Macedonians are not Slavs than we can easily break every group in Europe, because none is genetically homogeneous…Norwegians and Austrians are not the same, Russians and Serbs are not the same, French and Romanians are not the same etc., etc.
@Wilkolak…this is not some correction or suggestion to your post, I was just saying what I think about ethnic nomenclature.