Science. Closer to a single map of all human genetic diversity – Publimetro México

Madrid, 25 (European Press)

The Big Data Institute at Oxford University has taken a big step toward fully mapping the genetic relationships between humans: the only genealogy that traces our ancestors all.

The study was published in the journal Science.

The past two decades have seen extraordinary advances in human genetic research, generating genomic data for hundreds of thousands of individuals, including thousands of prehistoric people. This raises the exciting possibility of tracing the origins of human genetic diversity to produce a comprehensive map of how individuals around the world relate to one another.

So far, the main challenges of this vision have been to find a way to integrate genetic sequences from many different databases and to develop algorithms to handle data of this size. However, the new method published by researchers at Oxford University’s Big Data Institute can easily combine data from multiple sources and scale to accommodate millions of genetic sequences.

“Essentially, we’ve built a large family tree, a genealogical chain for all of humanity that models as closely as possible the history that gave birth to all of humanity,” Dr. Yan Wong, an evolutionary geneticist at the Big Data Institute and one of the lead authors, explained in a statement. The genetic diversity that we find in humans today. This genealogy allows us to learn how each person’s genetic sequence relates to others, along all points of the genome.”

Since individual genomic regions are inherited only from one parent, either the mother or the father, the origin of each point in the genome can be considered as a tree. The set of trees, known as a “sequence tree” or “ancestral recombination plot,” links genetic regions through time back to the ancestors where genetic variation first appeared.

Lead author Dr. Anthony Wilder Wons, who conducted the research as part of his Ph.D., used this research to form a vast network of relationships. We can then estimate when and where these ancestors lived. The strength of our approach is that it makes very few assumptions about the underlying data and can also include both modern and ancient DNA samples.”

The study combined data on modern and ancient human genomes from eight different databases and included a total of 3,609 individual genome sequences from 215 groups. Ancient genomes included samples found around the world ranging in age from 1,000 to more than 100,000 years. Algorithms predicted where common ancestors should reside in phylogenetic trees to explain patterns of genetic variation. The resulting network contained approximately 27 million ancestors.

After adding location data across these genomic samples, the authors used the network to estimate where the expected common ancestors lived. The findings successfully retrieve key events in the history of human evolution, including migration from Africa.

Although the genealogy map is already a very rich resource, the research team plans to make it more comprehensive by continuing to incorporate genetic data as it becomes available. Since tree sequences store data very efficiently, a data set can easily accommodate millions of additional genomes.

Dr Wong said: “This study paves the way for the next generation of DNA sequencing. As the quality of genomic sequences from both modern and ancient DNA samples improves, trees will become more accurate and we will eventually be able to create a single, unified map that explains the decline in all the human genetic diversity we see.” Today “.

Dr Wons added: “While humans are the focus of this study, the method is valid for most organisms, from orangutans to bacteria. It could be particularly useful in medical genetics, separating true associations between genetic regions and disease from false associations.” . Ties that arise from our common ancestral history.”