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Yahoo
5 days ago
- Business
- Yahoo
Genomes from ancient Maya people reveal collapse of population and civilization 1,200 years ago
When you buy through links on our articles, Future and its syndication partners may earn a commission. Skeletons buried near the ancient Maya city of Copán have revealed new clues about the collapse, but not total decimation, of the Maya civilization. A study of the genomes of seven people from the Classic Maya period (A.D. 250 to 900) of Copán in what is now western Honduras showed that the population dramatically shrank around 1,200 years ago. "Our findings indicate a decline in population size" among the Maya, study co-author Shigeki Nakagome, an assistant professor of genomic medicine at Trinity College Dublin, told Live Science in an email, which "aligns with a scenario proposed by archaeologists in which the population decreased but did not become entirely extinct." Nakagome and colleagues published their findings Wednesday (May 28) in the journal Current Biology. In their study, the researchers investigated the hypothesis that outsiders assumed power at Copán in the late 420s and explored how interactions between locals and non-locals created social and cultural change at this important Maya center. Copán was a major capital located at the extreme southeast of the Classic Maya civilization, functioning as a kind of crossroads between Central and South America. The royal dynasty that ruled for four centuries was established at Copán in A.D. 426 by a man known as K'inich Yax K'uk' Mo', who was an outsider according to inscriptions. Previous genomic and isotopic analyses of skeletons from other Maya sites have suggested that migration and gene flow were common, but the nature of that gene mixing at Copán had never before been investigated. Based on their sequencing of genomes of seven people buried at Copán, the researchers discovered that the people all had different maternal lineages. Two males, however, belonged to the same Y-chromosome lineage and were buried together: one male in a wealthy burial was a possible dynastic ruler and the other male was a potential sacrifice. But the men were not closely related. "Even though the dynastic ruler and the sacrificed individual share the same Y-chromosome haplogroup," Nakagome said, "we did not find any kinship." The lineage the men share is common among present-day Indigenous American populations, he said. Related: Secret of ancient Maya blue pigment revealed from cracks and clues on a dozen bowls from Chichén Itzá By comparing the seven ancient genomes to previously sequenced genomes across Siberia and the Americas, the researchers found strong evidence of genetic continuity in the Maya region from the Late Archaic period, roughly 3700 B.C. to 1000 B.C., to the present day. These genetic data suggest "the enduring persistence of local ancestry in the Maya region," the researchers wrote in the study. They also found that during the Classic Maya period, there was an influx of people with highland Mexican ancestry, possibly from other Maya sites such as Chichén Itzá. These "outsiders" — perhaps part of the ruling dynasty of Copán — mixed with the locals, creating a population with two main ancestries. RELATED STORIES —'Trash' found deep inside a Mexican cave turns out to be 500-year-old artifacts from a little-known culture —'Stunning' discovery reveals how the Maya rose up 4,000 years ago —Mysterious Maya underground structure unearthed in Mexico Delving further into the genomic data of the seven individuals, the researchers were able to estimate the size of the Maya population at specific points in time. According to their model, "the population in the Maya region appears to have experienced significant growth in effective size, reaching approximately 19,000 [people]" around A.D. 730, they wrote. The increase may be related to the advent of maize agriculture, which could have supported a larger population. Then, the population size began to decline around A.D. 750, "coinciding with the onset of the collapse of Classic Maya civilization," they wrote. Although the population dramatically dwindled with the collapse of the Maya political system, the researchers ultimately found support in their analysis for population persistence through time. "The genetic continuity observed in our study supports the idea that the population was not replaced by another group after the collapse." The genomes of the more than 7 million present-day Maya are closely related to the genomes of ancient Maya.
Irish Independent
5 days ago
- Science
- Irish Independent
Genetic clues to the rise of the Mayan civilisation uncovered by TCD geneticist
That's according to new research by a Trinity College Dublin (TCD) geneticist reported today in the journal Current Biology. Scientists previously found that present day Maya people carry genes from both the traditional local Maya ancestors and Mexican highlanders. 'What makes our findings significant is that we identified this gene flow starting around the beginning of the Classic period,' said Shigeki Nakagome, Ussher Assistant Professor in Genomic Medicine, School of Medicine, TCD. The Classic period of Mayan civilisation - when it was at its peak - scholars say was from around 250 AD to 950 AD, after which it declined. 'Archaeological evidence has long suggested that a possible connection between the Classic Maya states and regions in highland Mexico,' said professor Shigeki. 'This suggests that interaction between these regions may have played a role in the rise of Classic Maya civilisation.' The civilisation flourished primarily in present-day southeastern Mexico, Guatemala, Belize, and parts of Honduras and El Salvador. At its height, the Mayans built cities which were huge by the standard of the time, made up of monumental stone structures, and pyramid temples. They became renowned for a sophisticated writing system, advances in mathematics and astronomy, and skill in crafts like sculpture and pottery. 'Despite extensive archaeological research, many aspects of their ancestry and population history remain poorly understood,' said Prof Nakagome. The TCD researchers used ancient genomics to analyse DNA from seven people who lived in Copán in Honduras during the Classic Mayan period. Ancient genomics is the study of genomes (a genome being the entire DNA in a single cell) recovered from the bones or teeth of ancient people. This enabled them to investigate the genetic ancestry of these individuals. 'We focused on the petrous portion of the temporal bone, a dense part of the skull known for its exceptional DNA preservation.' This area of bone is known to yield higher quantities of ancient DNA compared to other parts of the human skeleton. However, Nakagome and his team found that studying these ancient DNA samples was far more difficult than investigating modern DNA. 'After death, DNA begins to degrade and fragment due to environmental factors like temperature, humidity, and microbial activity. 'As a result, ancient DNA is often highly fragmented, chemically modified and present in very low quantities, requiring specialised techniques and strict contamination controls to recover and analyse it accurately.' The results indicated that there was an influx of people from Highland Mexico into the Mayan lowland areas during the early to middle Classic period. 'This shows that the rise of the Classic Maya civilisation involved movement and interaction with people possibly from outside the Maya region.' The research also sheds some light on the fall of the Mayan people, beginning around 090 AD, which remains a famous and enduring scientific mystery. 'As the Mayan civilisation began to collapse near the of the classic period, we saw signs of a population decline.' 'This genetic evidence helps support the idea that major social and environmental changes had real demographic consequences.' The TCD researchers now plan to study more DNA from other ancient skeletal remains of people across a variety of locations in the Mayan world. This data will be compared to the archaeological and environmental historical record to gain further insights into the rise and fall of the Mayans.
