A study of mitochondrial DNA from 92 mummies and skeletons of indigenous Americans who lived from 8,600 to 500 years ago suggests the arrival of Europeans may have wiped out some populations in North, Central and South America. Scientists say some sort of catastrophe reduced the genetic diversity of indigenous peoples about 500 years ago. "We knew that Native Americans living today have a relatively low genetic diversity, meaning it is highly likely that sometime in the past, they lost some of their genetic diversity in what we call a bottleneck," said Bastien Llamas, lead author of the study published in Science Advances.