This video says about itself:
16 May 2014
Scientists have found what they believe is the oldest nearly complete, genetically intact human skeleton in the Americas within a flooded cave in Mexico’s Yucatán Peninsula.
16 May 2014
Bones From a Watery ‘Black Hole’ Confirm First American Origins
Most researchers agree that the earliest Americans came over from Asia via the Bering Strait between Siberia and Alaska, beginning at least 15,000 years ago. But many have long puzzled over findings that some of the earliest known skeletons—with long skulls and prominent foreheads—do not resemble today’s Native Americans, who tend to have rounder skulls and flatter faces. Some have even suggested that at least two migrations into the Americas were involved, one earlier and one later.
But the discovery of a nearly 13,000-year-old teenage girl in an underwater cave in Mexico’s Yucatán Peninsula argues against that hypothesis. The girl had the skull features of older skeletons, but the genetic profile of some of today’s Native Americans—suggesting that the anatomical differences were the result of evolutionary changes after the first Americans left Asia, rather than evidence of separate ancestry.
Also from Science:
Because of differences in craniofacial morphology and dentition between the earliest American skeletons and modern Native Americans, separate origins have been postulated for them, despite genetic evidence to the contrary. We describe a near-complete human skeleton with an intact cranium and preserved DNA found with extinct fauna in a submerged cave on Mexico’s Yucatan Peninsula. This skeleton dates to between 13,000 and 12,000 calendar years ago and has Paleoamerican craniofacial characteristics and a Beringian-derived mitochondrial DNA (mtDNA) haplogroup (D1). Thus, the differences between Paleoamericans and Native Americans probably resulted from in situ evolution rather than separate ancestry.