Actually the Greeks and Romans are partially the same, both
mediterranean, Greeks and Romans were both J2 haplotype. Romans were a
mix of Celts and Mediterranean Etruscans. Etruscans and Greeks are the
same people genetically. Proto Greeks (Dorians and Myceneans) were R1a
northerners probably of Seima-turbino culture. Indigenous minoans and
Pelasgians of Greece were Mediterranean like Etruscans. In fact that's
how mediterranean J2 got spread around Europe - by the Romans.
http://www.youtube.com/watch?v=aZAunpOGv8k