Chichén Itzá Rituals Revealed Through DNA
Chichén Itzá, the ancient Mayan city in Mexico's Yucatán Peninsula, has long been associated with sacrifice, with hundreds of skeletal remains unearthed from its temples, sacred cenotes, and subterranean caves.
Longstanding Perception Challenged
A long-held perception has been that sacrifice victims were predominantly young women. This notion has seeped into the popular imagination and has been difficult to dispel, despite recent research suggesting that both men and women, as well as children, were among those sacrificed.
A study published in the journal Nature on June 13th now adds further nuance to the story of Mayan sacrifice.
Ancient DNA Sheds Light
Based on ancient DNA collected from the remains of 64 individuals who archaeologists believe were ritually sacrificed and subsequently placed in an underground chamber, the new analysis reveals that the victims were all male children, many of whom were closely related.
"These were surprising findings," said study lead author Rodrigo Barquera, researcher in the Department of Archaeology at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. "We found a burial consisting entirely of males, many of whom were genetically related, including two pairs of twins."
Debunking the Myth
Rubén Mendoza, archaeologist and professor in the Department of Social Sciences and Global Studies at California State University, Northridge, says the popular notion that the Maya exclusively sacrificed women or young girls is largely a myth stemming from stories about Chichén Itzá's sacred cenote, or sinkhole, called the Cenote of Monterey.
"The popular image of Maya sacrifice is this vision of young women, or more specifically 'virgins,' being thrown to their death in sacred sinkholes," Mendoza said.
Unraveling the mystery of Mayan sacrifice has been particularly challenging because it can be difficult to determine the sex of a child's skeleton solely through bone analysis. While the pelvis and a few other bones can reveal the sex of an adult skeleton, these distinguishing characteristics only appear at puberty, and even in adults, natural variation can make precise determination difficult.
DNA to the Rescue
This difficulty makes genetic analysis particularly valuable, says study co-author Christina Warinner, John L. Loeb Associate Professor of the Social Sciences and of Anthropology at Harvard University and Group Leader at the Max Planck Institute for Evolutionary Anthropology. But the application of ancient DNA, which has revolutionized archaeological research in Europe and higher-latitude regions, has been more limited in the tropics because DNA degrades more readily in warm conditions. However, recent advances in ancient DNA technology are expanding its reach.
"We're getting better and better at capturing even very small amounts of DNA," Warinner said. "We now have the ability to do genome-scale studies and apply ancient DNA as a tool to understand the past in Mesoamerica."
The new research team was able to extract and sequence ancient DNA from 64 of the approximately 100 individuals whose remains were found scattered across an underground burial chamber discovered in 1967 about 400 meters from the sacred cenote at Chichén Itzá.
Using radiocarbon dating, the team determined that the underground chamber was used for burials over a period of 500 years, although the majority of the children's remains that the team analyzed were laid to rest there between 800 and 1,000 CE â€" during the height of Chichén Itzá's regional political power.
DNA analysis revealed that all of the children were male, drawn from the Maya population of the time, and that at least a quarter of the group were closely related to at least one other individual in the burial chamber. The group included two sets of twins, as well as siblings and cousins. Most of the boys were between the ages of 3 and 6 when they died.
Connecting to Present-Day Communities
"This is the first time that genetic material recovered from ancient Maya burials has been detailed enough to produce genome sequences," Warinner said, "providing a richer picture of who these victims were and how they were related to one another."
By comparing the ancient DNA to the DNA of 68 present-day Maya residents from the community of Tixcacaltuyub, the researchers found that the two groups share a close genetic connection.
The team also showed how the present-day residents' immune systems have been shaped over time by the biological impact of the diseases introduced by European colonizers. The researchers found that present-day Maya people have genetic variants that may protect them against salmonella, thought to be the pathogen that caused the devastating cocoliztli epidemic of 1545.
MarÃa Ermila Moo-Mesta, study co-author and professor of Maya Studies at the Autonomous University of Yucatan, said the new research is particularly meaningful to her in terms of preserving "the historical memory of the Maya people."
Summary
New research using ancient DNA has shed light on the mysteries of Mayan sacrifice practices at the ancient city of Chichén Itzá. Contrary to popular belief, the victims were predominantly young boys, many of whom were closely related. The study also reveals connections between the ancient and present-day Maya population, highlighting the ongoing impact of historical events on the genetic makeup of communities.