A research team from Oxford and UCL has developed a map which shows history’s impact on the ancestral genetic mix of 95 different populations around the globe.
Using an interactive map, the work displays, dates and characterises genetic mixing between populations, showing the impact of major events such as Genghis Khan’s transcontinental empire, European colonialism, the Arab slave trade and European traders on the Silk Road mixing with people in China.
Dr Simon Myers, from Oxford University’s Department of Statistics and Wellcome Trust Centre for Human Genetics and co-senior author of the study, said, “DNA really has the power to tell stories and uncover details of humanity’s past.
“Because our approach uses only genetic data, it provides information independent from other sources. Many of our genetic observations match historical events, and we also see evidence of previously unrecorded genetic mixing.
“For example, the DNA of the Tu people in modern China suggests that in around 1200CE, Europeans similar to modern Greeks mixed with an otherwise Chinese-like population. Plausibly, the source of this European-like DNA might be merchants travelling the nearby Silk Road.”
The research was conducted using a technique called ‘Globetrotter’, which consists in analysing information across the whole genome in order to identify shared genes, even though individual mutations carry only weak signals about where a person is from. The study was conducted on the genomes of 1490 individuals from 95 populations around the world.
Dr Garrett Hellenthal of the UCL Genetics institute and lead author of the study, said “What amazes me most is simply how well our technique works.”
He continued, “We identify distinct events happening at different times among groups sampled within Pakistan, with some inheriting DNA from sub-Saharan Africa, perhaps related to the Arab Slave Trade, others from East Asia, and yet another from ancient Europe. Nearly all our populations show mixing events, so they are very common throughout recent history and often involve people migrating over large distances.”
Using genome data from 1,490 individuals across the 95 areas, advanced statistical analysis has identified groupings of DNA shared between individuals from varying groups.
As co-author Dr Daniel Falush was reported to have said, “Each population has a particular genetic ‘palette’. If you were to paint the genomes of people in modern-day Maya, for example, you would use a mixed palette with colours from Spanish-like, West African and Native American DNA. This mix dates back to around 1670CE, consistent with historical accounts describing Spanish and West African people entering the Americas around that time.
Dr Myers added, ‘’Understanding well the genetic similarities and differences between human populations is key for public health. Some populations are more at risk of certain diseases than others, and drug efficacy is also known to vary significantly. Rare genetic mutations are particularly likely to show strong differences between populations, and understanding their role in our health is an area of intense current research efforts.
“We hope in future to include even more detailed sequencing, to spot these rare mutations and better understand their global spread. Our method should be even more powerful when applied to these future data sets, providing rich opportunities for future work.”
The intriguing results of the research have been met with interest from students. Taylor Jaszewski, a visiting student studying History and Politics at St Anne’s, said, “The recent research completed on the details of the human genome in comparison with historical events is absolutely fascinating. This work represents a clear opportunity for the hard sciences and the humanities to work hand in hand and develop a more accurate account of our past.”
Jae Kwon, a biologist and visiting student also at St Anne’s, said, “This is amazing research which shows all the possibilities of pursuing genomic studies. Hopefully it will lead to further insights.”
