Ancient genomes reveal legacies of human sacrifice and mediaeval epidemics Premium

The new field of archaeogenetics helps scientists explore the history of burial practices, genetic studies, and Mayan sacrifices to uncover ancient mysteries with modern insights.

People’s practice of burying human remains throughout modern history echoes diverse cultural, spiritual, and social beliefs, and is often considered to be a line in the sands of time between modern and ancient humans. Studying burial practices is a complex endeavour, however: it’s hard to say if some prehistoric cave burials are intentional commemorations or remains covered by sediment over time, for example.

Nevertheless, researchers have recorded the practice of burying since the time of our now-extinct Neanderthal ancestors. The oldest intentional modern human burial dates to more than 100,000 years ago, in a cave in Israel. This timeline overlaps with the discovery of the skeletal remains of a roughly three-year-old child buried in Kenya some 80,000 years ago.

Burial practices evolved with advancing human civilisations, with the construction of elaborate mausoleums (that continue to date). The pyramids of Egypt were monumental tombs for the pharaohs; the Mughal emperor Shah Jahan commissioned the Taj Mahal in Agra as a mausoleum for his wife. These structures reflect an enduring human desire to honour the dead and remember them.

The handful of well-preserved skeletal remains at ancient burial sites also open a window into the dietary habits, environmental adaptations, microevolutionary characteristics, biological kinship, sex, and genetic history of the respective population. These sites, spread worldwide, have thus been sites of intense scientific investigation as well. Some famous examples include the Tollund Man Bog Bodies in Denmark and the Thebes Tombs in Egypt.

Studies of these sites have accelerated in the last decade thanks to rapid technological advances in genome-sequencing and medical genetics, which have expanded to seed the new fields of archaeogenetics and evolutionary medicine. Of late, researchers have used the tools and concepts therein to understand the origins of the bubonic plague pandemic, the evolution of malarial parasites, the spread of the mpox virus, and even the occurrence of Down’s syndrome in ancient genomes.

Chichén Itzá is an ancient Mayan city located in modern-day Mexico. It is known for its grand architecture and iconic ceremonial temples, built around 800-1000 AD. The temples are also infamous for having been the site of human sacrifices made as ritual offerings, and have been under constant archaeological investigation for more than a century.

The offerings were deposited in an enormous sinkhole or a subterranean cistern called the ‘Sacred Cenote’. In Mayan culture, these subterranean features were often associated with water and rain. The Sacred Cenote in Chichén Itzá holds the skeletal remains of more than 200 ritually sacrificed individuals, many of them children or adolescents. But we don’t know much about the lives of these individuals or their biological relationship (if any) with contemporary inhabitants of the region. European colonists used to believe these children/adolescents were ‘obtained’ by kidnapping, purchase, or through the exchange of gifts with other nations.