Is the Aztec and Mayan Civilizations from the descendents of the native americas?

Yes, of course. since the first evidence of humans populating the Americas certainly back as far as 13,000 yrs ago is evident, then the Aztecs and Mayas were but one of many local cultures that evolved from the 'Native Americans'. I don't think they like that designation. How would you like to be referred to as 'former loyal British subjects'?