Complex sentence: In Greece, J2a is more common in the south (eg Crete) and south Italy; whilst J2b (J2-M12) is more common in Thessaly, Macedonia and central northern Italy.
Split into simpler sentences: In Greece, J2a is more common in the south (eg Crete) and south Italy. Whilst J2b (m12) is more common in Thessaly and Macedonia and central northern Italy.