Hotly Debated Origins of Pre-Inca Civilization of Tiwanaku Revealed by Genetic Study
Tiwanaku – one of the largest Pre-Columbian settlements and archaeological sites, located in western Bolivia, near Lake Titicaca, has hotly debated origins. Even its name, or what would have been known to the inhabitants, is lost as there was no written language. Historians roughly agree that the civilization emerged somewhere around the 6 th century AD, and collapsed around 600 years later around the 12 th century AD. While little is known of the Tiwanakus, a fabulous new study published in Sciences Advances has shed light on one important aspect: there was a greater degree of genetic homogeneity than previously thought.
Tiwanaku’s social complexity is seen on par with civilizations in the Indus and Nile River valley, and is a very important pre-Inca polity in the region. A series of archaeological studies have shown the rise, fall, and expansion of the Tiwanaku culture, but otherwise, information is very scarce.
Locally Homogenous and Centrally Heterogenous
The team of researchers, led by Centre of New Technologies at the University of Warsaw (CENT) geneticist Dr. Danijela Popović, analyzed 17 low-coverage genomes from individuals dated between 300 and 1500 AD, from the Lake Titicaca basin, and demonstrated a degree of genetic continuity. This led them to believe that “substantial cultural and political changes in the region were not accompanied by large-scale population movements.” In other words, the rural populations living around Lake Titicaca were not affected genetically by any major external migrations for several hundred years, reports Heritage Daily .
However, the ritual center of Tiwanaku revealed a converse reality – high diversity in population, with a mix of primarily local genetic ancestry and foreign provenance from as far as the Amazon basin. This high level of DNA migration indicated that the ritual center was a place for pilgrims and travellers from across the southern Andes, who were welcomed with open arms. Further research, however, indicated that it was lesser the pilgrims and more a case of mixed ancestry. This re-emphasized that Tiwanaku was a complex socio-political empire, with far reaching polity.
“We discovered the presence of newcomers from southern Peru, and even one individual from the distant Amazon. He was sacrificed,” said Dr. Popović to PAP. Two other individuals showed mixed ancestry, both from the Lake Titicaca area, along with the Amazon area. Prof. Ziolkowski from (CENT) added that earlier artefacts associated with the Amazon region were attributed to trade, as there was no evidence that suggested their physical presence in western Bolivia – this has now been refuted.
Temple Kalasasaya, an important pre Columbian Archaeological Site in Tiwanaku, Bolivia. Source: Cezary Wojtkowski / Adobe Stock
The Science of Genetic Reconstruction
The 17 individuals who were successfully analyzed was a struggle in itself – a hundred samples were considered and had to be tossed aside, as less than a fifth could be effectively utilised. The reason, of course, being the ravages of time on organic matter. The fossil DNA was severely fragmented and degraded. "Despite the difficulties, using the most modern techniques, we have doubled the amount of known genomic data available for pre-Columbian populations in Bolivia", noted Dr. Popović.
The study was a combination of intense work led by a group of palaeogeneticists from CENT and another group of foreign researchers. Palaeogenetic analysis was conducted at Laboratory of Palaeogenetics and Conservation Genetics at CENT, and crucial funding was provided by the National Science Centre.
Tiwanaku had been previously understood and assessed through the prism of its great monuments that now lie in ruin, and bodies were aged with the age of the monument – a highly inaccurate practice. These samples, however, helped put the human beings under the scanner and conduct genetic research through radioactive carbon dating in the new AMS or Accelerator Mass Spectrometry technique, wherein, dating involves accelerating the ions to extraordinarily high kinetic energies. This technique has a much higher rate of accuracy.
Lake Titicaca. Source: Aleksandar Todorovic / Adobe Stock
Tiwanaku: The Rise and Fall of the Great Empire
Why and how Tiwanaku collapsed is still a mystery, despite this research and study. Perhaps, it was a decades-long drought that had led to the disintegration of the floodplain farming system, though another recent study on Tiwanaku revealed that the fields were still cultivated – this theory is too simple, and environmentally deterministic, which is not a practice that modern historians endorse with the kind of science available today.
Similar to the Indus Valley civilization all the way across in the Indian subcontinent, which also collapsed without a decipherable language, the Tiwanaku civilization perhaps experienced some form of social rebellion. This deduction could be drawn by looking at the intentional destruction of certain temples, according to Professor Ziolkowski. Later on in the empire’s history, it is possible that the emergence of a new social elite caused the empire’s collapse – evidenced from the sudden increase and intensification in human sacrificial rituals.
In conclusion, and on the whole, the population of the basin was rather genetically homogenous from around 300 AD, until the arrival of the Europeans. At certain sites, like Lukurmata, it was found that there was no major genetic alteration for over 12 centuries. Acknowledging the limitations of time, and the small sample sizes, the team requires more genetic, isotopic, and archaeological data on the whole, to come to larger and more conclusive theories.
Top image: Tiwanaku (Tiahuanaco), Pre-Columbian archaeological site, Bolivia Source: worldwonders / Adobe Stock
By Sahir Pandey
Popovic, D., Molak, M., et al . 2021. Ancient genomes reveal long-range influence of the pre-Columbian culture and site of Tiwanaku . Sciences Advances, 7(39). Available at: https://www.science.org/doi/10.1126/sciadv.abg7261.
Heritage Daily. 2021. Genetic study reveals new insights into the pre-Inca Tiwanaku civilisation . Available at: https://www.heritagedaily.com/2021/10/genetic-study-reveals-new-insights-into-the-pre-inca-tiwanaku-civilisation/141628.