[Rolando González-José, of the University of Barcelona, Spain] thinks the formation of the Sonora desert isolated the Pericú for thousands of years, but they vanished when Europeans disrupted their culture. González-José measured 33 Pericú skulls and found their features were similar to those of the ancient Brazilian skulls. [For example.]This backs the idea that a first wave of long, narrow skulled people from south-east Asia colonised the Americas about 14,000 years ago. These were followed by a second wave of people from north-east Asia about 11,000 years ago, who had short skulls.
The above source based on a Nature article [abstract], which I'll have to go look up.
(More Kennewick Man links here.)