The Origin of the Scythians

Scythians were a blend of Middle-Eastern and north European-like people.

Their Middle-Eastern nature can be confirmed by haplogroup G, which extends as far north as the boreal zone: 

                                 Along with haplogroup J2, reaches as far north as south Siberia:

Also the west-Asian genetic component in MDLP: 

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And finally the presence of Middle-Eastern mtDNA:

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^U3 and U1a are rare throughout Europe, but both are found highest in the south Caucasus among the Svans of Georgia. 

So while the Proto-Indo-Europeans may have been north-east European like, the Scythians themselves were a mix of N-E European and Middle-Eastern.

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The Gedrosia component that Tuvans, Mongols and Altains share is also indicative of at least  partial west-Asian origin of Scythians and early Indo-Iranians:

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