Interactive map of human genetic history revealed

February 13, 2014
Admixture sources for Mozabite group. Credit: The Chromosome Painting Collective

The interactive map, produced by researchers from Oxford University and UCL (University College London), details the histories of genetic mixing between each of the 95 populations across Europe, Africa, Asia and South America spanning the last four millennia.

The study, published this week in Science, simultaneously identifies, dates and characterises genetic mixing between populations. To do this, the researchers developed sophisticated statistical methods to analyse the DNA of 1490 individuals in 95 populations around the world. The work was chiefly funded by the Wellcome Trust and Royal Society.

'DNA really has the power to tell stories and uncover details of humanity's past.' said Dr Simon Myers of Oxford University's Department of Statistics and Wellcome Trust Centre for Human Genetics, co-senior author of the study.

'Because our approach uses only genetic data, it provides information independent from other sources. Many of our genetic observations match , 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.'

Selected admixture events. Boxes show historical events, while blobs show dates inferred using genetic data, including the statistical uncertainty around them. Credit: The Chromosome Painting Collective

The powerful technique, christened 'Globetrotter', provides insight into past events such as the genetic legacy of the Mongol Empire. Historical records suggest that the Hazara people of Pakistan are partially descended from Mongol warriors, and this study found clear evidence of Mongol DNA entering the population during the period of the Mongol Empire. Six other populations, from as far west as Turkey, showed similar evidence of genetic mixing with Mongols around the same time.

'What amazes me most is simply how well our technique works,' said Dr Garrett Hellenthal of the UCL Genetics Institute, lead author of the study. 'Although individual mutations carry only weak signals about where a person is from, by adding information across the whole genome we can reconstruct these mixing events. Sometimes individuals sampled from nearby regions can have surprisingly different sources of mixing.

'For example, 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.'

The team used genome data for all 1490 individuals to identify 'chunks' of DNA that were shared between individuals from different populations. Populations sharing more ancestry share more chunks, and individual chunks give clues about the underlying ancestry along chromosomes.

Selected admixture events inferred using genetic data. Locations and ancestry proportions contributed by incoming group. Different incoming groups are represented by the different colors highlighted in the previous image. Credit: The Chromosome Painting Collective

'Each has a particular genetic 'palette', said Dr Daniel Falush of the Max Planck Institute for Evolutionary Anthropology in Leipzig, co-senior author of the study. '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. Though we can't directly sample DNA from the groups that mixed in the past, we can capture much of the DNA of these original groups as persisting, within a mixed palette of modern-day groups. This is a very exciting development.'

As well as providing fresh insights into historical events, the new research might have implications for how DNA impacts health and disease in different populations.

This is a schematic of the admixture process. Credit: The chromosome painting collective

'Understanding well the genetic similarities and differences between human populations is key for public health,' said Dr Simon Myers. '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.'

Explore further: Seven new genetic regions linked to type 2 diabetes

More information: Paper: "A Genetic Atlas of Human Admixture History," by G. Hellenthal et al. Science, 2014.

The interactive map can be accessed at admixturemap.paintmychromosomes.com/

For additional information about the work and its main findings, please see the FAQ at www.well.ox.ac.uk/~gav/admixtu … al/resources/FAQ.pdf

Related Stories

Seven new genetic regions linked to type 2 diabetes

February 9, 2014
Seven new genetic regions associated with type 2 diabetes have been identified in the largest study to date of the genetic basis of the disease.

Population genetics reveals shared ancestries

May 24, 2011
More than just a tool for predicting health, modern genetics is upending long-held assumptions about who we are. A new study by Harvard researchers casts new light on the intermingling and migration of European, Middle Eastern ...

Neanderthal lineages excavated from modern human genomes

January 29, 2014
A substantial fraction of the Neanderthal genome persists in modern human populations. A new approach applied to analyzing whole-genome sequencing data from 665 people from Europe and East Asia shows that more than 20 percent ...

New research raises doubts about whether modern humans and Neanderthals interbred

August 13, 2012
New research raises questions about the theory that modern humans and Neanderthals at some point interbred, known as hybridisation. The findings of a study by researchers at the University of Cambridge suggests that common ...

Recommended for you

Scientists provide insight into genetic basis of neuropsychiatric disorders

July 21, 2017
A study by scientists at the Children's Medical Center Research Institute at UT Southwestern (CRI) is providing insight into the genetic basis of neuropsychiatric disorders. In this research, the first mouse model of a mutation ...

Scientists identify new way cells turn off genes

July 19, 2017
Cells have more than one trick up their sleeve for controlling certain genes that regulate fetal growth and development.

South Asian genomes could be boon for disease research, scientists say

July 18, 2017
The Indian subcontinent's massive population is nearing 1.5 billion according to recent accounts. But that population is far from monolithic; it's made up of nearly 5,000 well-defined sub-groups, making the region one of ...

Mutant yeast reveals details of the aberrant genomic machinery of children's high-grade gliomas

July 18, 2017
St. Jude Children's Research Hospital biologists have used engineered yeast cells to discover how a mutation that is frequently found in pediatric brain tumor high-grade glioma triggers a cascade of genomic malfunctions.

Late-breaking mutations may play an important role in autism

July 17, 2017
A study of nearly 6,000 families, combining three genetic sequencing technologies, finds that mutations that occur after conception play an important role in autism. A team led by investigators at Boston Children's Hospital ...

Newly discovered gene variants link innate immunity and Alzheimer's disease

July 17, 2017
Three new gene variants, found in a genome wide association study of Alzheimer's disease (AD), point to the brain's immune cells in the onset of the disorder. These genes encode three proteins that are found in microglia, ...

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Expiorer
not rated yet Feb 14, 2014
The graph is interesting. They have to Inbreed to keep graph in just 2 colors.
Osiris1
not rated yet Feb 14, 2014
That map appears to implicate the central south asian region near Tashkent as the center of mass of humanity, and maybe its origin inasmuch I separately read of some anthropological archaeological digs of sites in Turkestan over 8000 years old of actual towns laid out on square lots and blocks. These were extensive and probably housed in excess of 50 thousand people. They had indoor plumbing, good roofs and gravity designed underground sanitation systems.....all over 8000 years ago. Seems we have lots to learn of our prehistory....and then we had somebody fatuously proclaim that the domestication of camels took place more recent than 1000 BC.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.