Subject-verb agreement, shown in the tree on the left, is a case of head-marking because the singular subject John requires the inflectional suffix -s to appear on the finite verb cheats, the head of the clause.
Dependent-marked noun phrases have a complementary distribution and are frequent in Africa, Eurasia, Australia, and New Guinea, the only area in which both types overlap appreciably.
[5][6] The Pacific Rim distribution of head-marking may reflect population movements beginning tens of thousands of years ago and founder effects.
Kusunda has traces in the Himalayas, and there are Caucasian enclaves, both of which are perhaps remnants of typology preceding the spreads of interior Eurasian language families.
Whether the diversity of types along the Pacific Coast reflects a great age or an overlay of more recent Eurasian colonizations on an earlier American stratum remains to be seen.