Three ancient populations from Middle America have been studied: a 500–675 YBP sample of Post-Classic Aztec from Tlatelolco, Mexico, a 480–1400 YBP Maya sample from Xcaret, Mexico and a 750–1300 YBP Maya sample from Copán, Honduras. The two ancient Mexican populations exhibit a high frequency of haplogroup A, like many modern Middle American populations, but the ancient Maya population from Copán belongs primarily to haplogroup C.
The first Mexicans were Olmec. Their culture flourished from around 1200 B.C. and lasted to about 200 A.D. These folks were native to America & were in no way linked to any other group (outside of the six founder haplogroups) until after Columbus' arrival and conquest.
Olmec colossal heads. The most recognized aspect of the Olmec civilization are the enormous helmeted heads. The Olmec are now recognized as the predecessors of the Maya and Aztec civilizations. Olmec head, Museo de Antropología, Xalapa Olmec head, Veracruz, circa 1942. The Olmec are now recognized as the predecessors of the Maya and Aztec civilizations. Many of the scientific and cultural discoveries previously credited to those cultures are now recognized as being discovered first by the Olmec.