The Himalayas contain many unique and ancient cultures. Recently, a team of researchers and mountaineers led by archaeologist Dr. Mark Aldenderfer began unraveling mysteries surrounding peoples who lived thousands of years ago in the caves of Nepal's Upper Mustang region.

Aldenderfer led a 20-day expedition to the Upper Mustang to explore mysterious communal graves discovered in the 1990s. The skeletons and burial artifacts were found in caves on the sides of cliffs. To identify possible burial sites, Aldenderfer and his team, including bioarchaeologist Dr. Jackie Eng and seven-time Everest climber Pete Athans, combed the region for deep caves on the brink of collapse. The bones that Aldenderfer's team collected, thought to be the mysterious Membrak people, were then cleaned, pieced together, and analyzed.

For Dr. Eng, when an ancient communal grave is uncovered, her first job is to identify the number of individuals in the burial context. She does this by counting the number of left femurs. Bones hold important information about an individual's age, sex, and lifestyle. A fracture can be evidence of violence or of environmental peril, for example. From analyzing the bones, Eng can create a sort of character narrative for each individual, illustrating what life might have been like thousands of years ago in this high mountain environment.

For Aldenderfer, finding ancient human bones is exciting, but what he's really after are teeth and what he can learn from them. Most of the critical information held in the human body can be found in a single molar: analysis of dentine determines ancient DNA, while radiocarbon dating, and carbon and nitrogen isotopes in tooth enamel provide information about diet during childhood. Remarkably, strontium isotope analysis of tooth enamel, which forms during the neonatal period, can now tell us the birthplace of each individual.