The research, led by scientists from the University of Oxford’s Big Data Institute, combines human genomes from a variety of sources – both ancient and modern DNA – to better understand human history and development.
Just as a family tree shows how an individual is related to his parents or siblings, it is hereditary Lead author Anthony Wilder Wons, now a postdoctoral researcher at the Broad Institute at MIT and Harvard, told CNN that genealogy reveals the genes that two people have in common.
As such, it can show which points in the human genome individuals share genes and where they differ.
“Simply put, what we did is we created the largest human family tree ever,” Wons said. “We have a single lineage that traces the ancestors of all of humanity, and shows how we are all related to one another today.”
A resource means that anyone with access to their genetic information can find out when their ancestors moved to a particular place, and why they have certain genes.
“It’s basically understanding the whole story of human history written in our genes,” Wohns said.
However, it has proven difficult to combine different databases, merge ancient and modern genomes, and find ways to deal with such a large amount of data.
The Oxford team has developed algorithms to enable genome incorporation into their tool.
“That was one of our biggest innovations,” Wons said.
This, he said, allowed them to build the structure of what they called “human genetic genealogy” that had been talked about theoretically for nearly 30 years.
“We’re basically trying to break through the veil and see what that looks like,” he added.
As things stand, the genes of 3,609 people have been sequenced from 215 groups, some dating back more than 100,000 years. This method allows to extend this number to millions of genomes in the future.
The paper confirms current conclusions about human history, including that most human evolution occurred in Africa before big Wohns said the movement off the continent was about 70,000 years ago.
“It’s confirmation in many ways,” he said, adding that the data show that there is most genetic diversity in Africa and that the oldest human ancestors are on the continent. “It is clear that the majority of human evolution occurred in Africa.”
“First Draft” of Genetic Genealogy
However, the data also raises questions.
“It’s suggestive of unknown migrations that happened in the past,” Wons said.
For example, there is some evidence that human ancestors were in North America earlier than previously thought, although more research is needed to uncover unknown migrations, he said.
Wens likened the research to a “first draft” of human genetic genealogy, and said more work would help make it more accurate and comprehensive.
Adding more genomes will help do that, but in order to achieve complete accuracy we need to get the genome of every human who has ever lived, he said, which isn’t possible.
Wohns said he hopes other researchers in the field will use the resource, which is available for download along with instructions for use, as a basis to answer more specific questions about migration in certain geographic areas.
“It will be a really rich resource for future investigations into the history of human evolution,” he said.
Wons himself is working with AI researchers to try to get more accurate estimates of when and where human ancestors lived.
The method can also be used to develop the genealogy of any organism, including diseases such as SARS-CoV-2, the coronavirus that causes Covid-19, and Wohns plans to study the relationship between genetics and disease.
The ‘Big Promise’ of Evolutionary Studies
Anders Bergstrom, a postdoctoral fellow in evolutionary genomics at the Francis Crick Institute in London, told CNN that the study provides a new way to estimate how our DNA is related.
“Inferring tree-like lineages linking DNA between different people is the holy grail of genomics. It will never be fully resolved, but this new computational method takes an important step forward on this problem,” he said by email.
“The genealogy they deduce provides an incredibly rich insight into human genetic diversity and history. There is a lot of excitement in genomics now about the many possibilities offered by these new computational approaches.”
Pontus Skoglund, group head of the Ancient Genome Laboratory at the Francis Crick Institute, told CNN that the study shows this type of approach can extend to large databases.
“They therefore have great promise of benefit to medical genetics and evolutionary studies, and this paper is a huge step forward toward that,” Skoglund said by email.