Scythians were people who roamed the vast Eurasian and Central Asian steppes. Persians and Scythians are both Iranic people. Persians themselves were invaders/migrants from Eurasian Steppes but had settled in modern day Iran and assimilated the local population. They also become more civilized and developed a sophisticated culture different from Scythians. Some Scythians did invade Northern India and were assimilated into local culture and religion. I read somewhere that many Punjabis specially Sikhs tend to have some genetic similarities with Scythians.
Modern day Ukraine may have been the home land of some of the Scythian tribes. Their descendants were later known as Sarmations or Alani/Ard Alani/Alans. Today they still exist and are known as Ossetians.
Another theory is that some of them may have migrated towards north eastern Europe and become the modern day Slavs. But this theory is not widely supported by academics. Maybe a small population of Sarmatians may have been absorbed into different eastern European population to make a Slavic stock.
