I traveled to Yucatan, Mexico, with my daughter and son. We toured the pyramids at Chichen Itza, named one of the New Seven Wonders of the World sites. The city was built by the Mayans around 500 A.D., but it was abandoned around 700 years later. The ruins of Chichen Itza were rediscovered in the 19th century.
When the jungle foliage was cleared, it revealed ornate pyramids and Temples with serpent and jaguar designs carved into stone columns.
The visit to Chichen Itza was well worth the 2-hour drive each way from where we stayed in Playa del Carmen. I was lucky to have a driver/tour guide who spoke fluent English. Alejandro had gone to university and even had an MBA. But in Yucatan, the easiest job to get is with the tourist trade.
I had population genetics on my mind. Who doesn’t? What with the new ways of tracking ancestry by extracting DNA from burials that are thousands of years old, all sorts of discoveries are being made.
I shared with my tour guide an article in National Geographic I had read about how geneticists had studied a “ghost population” in southern Russia from burial mounds. A ghost population is one that no longer exists in an unmixed form. The term has nothing to do with poltergeists.
Five thousand years ago, this ghost population left behind burial mounds. They were nomadic and lived in tents as they took their cattle to grasslands across the steppes. There were no cities to excavate, and no evidence of their existence other than the discovery of these tombs.
With the skeletal remains, and the ornaments and weapons left behind with the departed, the scientists were able to construct a notion of how these nomads lived. And what their genetics looked like. They were able to sequence DNA from the bones they found and compare this sequence with DNA samples of modern populations living in Europe. Scientists discovered the steppe dwellers had donated a hefty amount of DNA to the Europeans. Around 50% of modern Scandinavian DNA is identical to that of the steppe dwellers.
Apparently, these horseback-riding, cattle-herding steppe nomads had migrated from their homeland in South Russia 5,000 years ago and traveled as far afield as the British Isles and the far reaches of Scandinavia.
The newcomers apparently overtook the native populations in Europe. They had the advantages of wheeled carts and domesticated horses and better bronze weapons. They brought these cutting-edge innovations into Europe, as well as an Indo-European language.
These cattle herders from the steppes were very generous with sharing their genes. They also brought the gene for lactose tolerance, meaning they could digest milk, which gave their descendants an evolutionary advantage in northern European climes.
Not only did they settle in Europe, the nomads also made an imprint on India. The steppe dwellers brought their genes, their innovations and their weapons with them to India. This explains why people in India speak Urdu, a language that is related to English. When Northern Indian genomes are sequenced, we again see a strong contribution of genes from the steppe nomads.
What was of particular interest, however, was a genetic signal that connected these steppe pastoralists with Native Americans! These steppe-dwellers apparently emerged from a parental population further east towards Mongolia. As did Native Americans who crossed the Bering Strait around 20,000 years, a journey which brings us back to the modern Mayans.
Alejandro listened to my long exposition on the origins of Indo-European languages and the genetics of Native Americans. It seemed to me that Chichen Itza was as good a place as any to speak highly of the ancient Mayans and the distinguished bloodlines they carried. It made for a lively conversation as we drove down a highway with jungle on either side.
This “ghost population” have been named the “Yamanya.” I hope we will be hearing more about them in the coming years. I also hope to return to the Mayan Riviera. It was a lovely trip.
Dr. Janet Tamaren 