A genetic analysis of head lice that have evolved in tandem with humans has revealed two distinct groups of lice that merged in the Americas as a result of Asian and European migrations.

Mummified mice found atop volcanoes in South America have long hinted that rodents forage on peaks as tall as 22,000 feet, but it turns out mice permanently live at these extreme heights.

An analysis suggests that annual temperature-related deaths in the U.S. could rise to one-third of the number caused by cancer if global warming hits 5.4 degrees Fahrenheit (3 degrees Celsius).

Previously, researchers thought that humans arrived in North America 13,000 years ago, but now they're finding much older evidence.

Data shows that America's excess death rates have mostly returned to pre-pandemic levels, reflecting the end of the public health crisis, experts say.

Humans were living in Brazil earlier than previously thought, prehistoric sloth-bone pendants suggest.

The linkage of the Americas had outsize impacts globally, and its controversial timing has similarly large implications for science.

The first wave of humans into the Americas during the last ice age may have hailed partly from northern China, according to a DNA study of ancient and modern Indigenous people.