Maya City's Rituals Revealed
Chichén Itzá, the ancient Maya city on Mexico's Yucatán Peninsula, has long been linked to ritual sacrifice, with hundreds of skeletal remains excavated from its temples, sacred cenotes, and subsurface caves.
The Victims: Unraveling Gender and Kinship
A deep-seated perception has persisted that the victims of sacrifice were predominantly young and female, an impression ingrained in the popular imagination that proved difficult to shake, even as recent research pointed to both males and females, as well as children, among the sacrificed.
A study published June 13 in the journal Nature adds unexpected detail to the Maya sacrificial picture. Based on ancient DNA collected from the remains of 64 individuals whom archaeologists believe were ritually sacrificed and then deposited in an underground chamber, the new analysis reveals that the victims were exclusively young boys, many of whom were closely related.
"That was a big surprise," said Rodrigo Barquera, the study's lead author and a researcher in the Department of Archaeology at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. "We found a burial with no distinction based on sex, with many individuals closely related, including two pairs of twins."
DNA Illuminates the Mystery
The gruesome notion that the Maya sacrificed only women or young girls is largely a myth rooted in sensationalized accounts of Chichén Itzá's sacred cenote, or wellspring, at the heart of the city, according to Rubén Mendoza, an archaeologist and professor in the Department of Social Sciences and Global Studies at California State University, Northridge.
"The Maya's sacrificial practices have been popularized in the media in terms of maidens or young women being sacrificed into a well," Mendoza said.
Yet the puzzle of Maya sacrifice has been difficult to solve because a child's skeletal remains alone cannot determine sex. While the pelvis and a few other bones can reveal the gender of adult skeletons, clear distinctions only emerge at puberty, and even in adults, natural variation can make definitive identification challenging.
This difficulty makes genetic analysis especially valuable, said study co-author Christina Warinner, the John L. Loeb Associate Professor of Social Sciences and Anthropology at Harvard University and a group leader at the Max Planck Institute for Evolutionary Anthropology. But the reach of ancient DNA, which has revolutionized archaeology in Europe and higher-latitude regions, has been more limited in the tropics, where DNA degrades easily in warm conditions. However, recent advances in ancient DNA technology are expanding its reach.
"We're getting better and better at recovering DNA from even very small amounts of it. We now have the ability to do large-scale genomic studies and apply ancient DNA as a tool for understanding the past in Mesoamerica," Warinner said.
Excavating a Maya Burial Chamber
The new research team was able to successfully extract and sequence ancient DNA from 64 of the approximately 100 individuals whose skeletal remains were found scattered within an underground storage chamber discovered in 1967 some 400 meters from the sacred cenote at Chichén Itzá.
The Archaeological Context
Using radiocarbon dating, the team determined that the underground chamber was used for over 500 years, although most of the juvenile remains that the team analyzed were buried there between A.D. 800 and 1000, a period when Chichén Itzá was at the height of its regional political power.
The DNA analysis revealed that all the children were male, chosen from the Maya population of their time, and at least a quarter were closely related to at least one other child in the chamber. The group included two pairs of twins as well as full and half-siblings. Most of the boys were between the ages of 3 and 6 when they died.
Connections to Present-Day Maya
Warinner said that with this study, for the first time, genetic material recovered from ancient Maya remains has been detailed enough to sequence their genomes, providing a richer picture of who these victims were and how they were related to one another.
By comparing the ancient DNA with the DNA of 68 present-day residents of the Maya community of Tixcacaltuyub, the researchers found shared genetic ancestry going back centuries.
The study also sheds light on how the immune systems of present-day Maya residents have been shaped by the biological toll of diseases introduced by European colonizers. The researchers found that people in the area today carry genetic variants likely to protect them against salmonella, the suspected pathogen responsible for the devastating cocoliztli epidemic of 1545.
María Ermila Moo-Mezeta, a co-author of the study and researcher of Maya studies at the Autonomous University of Yucatán, said the new research is highly significant to her work preserving "the historical memory of the Maya people."
Summary
The new study reveals that the victims of ritual sacrifice at the ancient Maya city of Chichén Itzá were exclusively young boys, many of whom were closely related. Ancient DNA analysis also suggests that modern-day Maya people are biologically connected to the sacrificed children and that their ancestors may have developed genetic immunity to diseases introduced by European colonizers.