Genetic analysis of the skeletons of 64 infant boys believed to have been sacrificed in the ancient Mayan city of Chichén Itzá more than a thousand years ago may shed light on the symbolic role that twins played in the myths and rituals of their civilization.
In 1967, the remains of more than 100 children were found in a repurposed chultúnor underground well, near the sacred sinkhole at the ceremonial center of the pre-Columbian city, which was one of the largest and most influential Maya settlements between AD 600 and 1000.
A study of 64 of the children determined that most of them in the chultún on Mexico’s Yucatán Peninsula between AD500 and 900. DNA tests showed that all the individuals analyzed were male, and that several were closely related, including two pairs of monozygotic twins. Most were estimated to be between three and six years old.
The location of the chultún – which is connected to a small underground cave – has led experts to speculate that it was the burial ground for children sacrificed to support maize cultivation cycles, or given as offerings to Chaac, the Mayan rain god.
Twins feature prominently in Mayan mythology and twin sacrifices are a central theme in the Popol Vuhthe sacred book of the indigenous Kʼicheʼ, one of the Maya peoples.
“In the Popol Vuhthe twins Hun Hunahpu and Vucub Hunahpu descend into the underworld and are sacrificed by the gods after a defeat in a ball game,” the researchers writes in Nature.
“The head of Hun Hunahpu is then hung in a gourd tree, where it impregnates a girl who gives birth to a second set of twins, Hunahpu and Xbalanque. These twins, known as the Hero Twins, then proceed to avenge their father and uncle by undergoing repeated cycles of sacrifice and resurrection to outwit the gods of the underworld.”
Given that underground structures were seen as entrances to the underworld, the researchers add, “the twins and relative sacrifices within the chultún at Chichén Itzá can remember rituals involving the hero twins”.
The study’s lead author, Rodrigo Barquera, from the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) in Germany, said that although ritual sacrifice was a common practice among ancient Mesoamerican populations, the biological relationships between sacrificial victims had not been previously described.
“We think that the people of Chichén Itzá were trying to symbolically repeat the Mayan mythological stories and the representation of the twin heroes in this ritual burial,” he said. “For Maya, and Mesoamerican cultures in general, death is the ultimate sacrifice and as such sacrifices are very important to their belief system.”
The study also contradicts an idea popular in the 20th century that the ancient Maya preferred female sacrifices.
The researchers extracted DNA from the petrous portion of the temporal bone, which houses the inner ear and has proven optimal for preserving ancient DNA.
“We only sampled the left portion because that would make sure we only sampled each individual once,” said MPI-EVA archaeogeneticist and study co-author Kathrin Nägele.
“From the genetic similarities of two individuals we can calculate the degree of genetic relationship. In this case, we found two pairs that were so alike they could only be identical twins, and at least three more that were full siblings. They could also have been twins, but fraternal twins, coming from two different eggs,” she said.
“This is the first time we can confidently identify identical twins in the archaeological record.”
The researchers compared the genomes of the boys with those of modern-day Mayan communities, including 68 people from the village of Tixcacaltuyub, near the ruins of Chichén Itzá. They identified genetic traits in modern Maya that likely arose from the immune system adaptations their ancestors developed during Spanish colonization.
However, despite their findings, the researchers could not determine exactly how the 64 boys died.
“There are no cut marks or evidence of trauma, which tells us how they are not dead,” Barquera said. “But we haven’t found a cause of death for them yet.”
Sacrifice remains the most likely explanation.
“Back then, children who died of disease usually died within the first two years of life,” Barquera told El País. “It is rare to find so many dead between the ages of three and six. Also, if this was a funeral we would see a mix of genders, but here there is a clear pre-selection of men. Many of them were related. And we also got two sets of twins. The possibility that this is a product of chance is practically zero.”
Christina Warinner, a biomolecular archaeologist from Harvard University and one of the study’s co-authors, said efforts to eradicate Maya religious beliefs and activities – which included the systematic burning of thousands of Maya books and texts during the Spanish colonial period included – led to the destruction. of much historical evidence.
“As a result, there are many gaps in our knowledge about the specific ritual practices performed by the ancient Maya – and especially their meaning,” she said. “Among these, human sacrifice remains one of the most misunderstood ritual acts.”
