Where are the ancestors of all people: the largest human family tree ever built

　　The ancestors of all are here

　　Largest human family tree ever built

　　Science and Technology Daily, Beijing, February 24 (Reporter Zhang Mengran) Researchers at the University of Oxford's Big Data Institute in the United Kingdom have taken an important step in mapping the entire genetic relationship between humans: a single family tree that traces all of us. ancestor.

The study was published in the journal Science on the 24th.

　　This new genealogical network of human genetic diversity reveals in unprecedented detail how individuals around the world are related to each other.

The study predicts the common ancestor of humans, including when and where they roughly lived, and analyzes and recovers major events in human evolutionary history, such as the emergence of Africa.

Fundamental methods of research may have broad application in medical research, such as identifying genetic predictors of disease risk.

　　Tracing the origins of human genetic diversity to generate a complete map of how individuals around the world are related to each other, the main challenge in this vision is to find a way to combine genome sequences from many different databases and to develop algorithms to deal with this scale. data.

The new method released by researchers at the University of Oxford's Big Data Institute can easily combine data from multiple sources and scale to accommodate millions of genome sequences.

　　Dr Yan Huang, an evolutionary geneticist at the Big Data Institute and one of the paper's lead authors, explained: "We've basically built a giant family tree, a family tree of all humans that simulates, as accurately as possible, the processes that gave rise to all humans. History. The genetic variation we find in humans today, this family tree allows us to see how each individual's genetic sequence is related to each other along all points of the genome."

　　Since a single genomic region is inherited only from one parent, whether mother or father, the ancestry at each point on the genome can be considered a tree.

Known as a "tree sequence" or "ancestral recombination map," this set of trees links genetic regions through time to the ancestors where genetic variation first occurred.

　　"Essentially, we are reconstructing the genomes of our ancestors and using them to form a vast network of relationships," the researchers said. "We can then estimate when and where those ancestors lived. The power of this approach is that it provides insight into the underlying data. There are few hypotheses and can also include modern and ancient DNA samples."

　　The study integrated modern and ancient human genome data from 8 different databases, including a total of 3609 individual genome sequences from 215 populations.

Ancient genomes include samples found around the world ranging in age from 1,000 to 100,000 years old.

The algorithm predicts where in the evolutionary tree a common ancestor must exist to explain patterns of genetic variation.

The resulting network contained nearly 27 million ancestors.

　　After adding location data to these sample genomes, the researchers used the network to estimate where the predicted common ancestor lived.

The results successfully recreated key events in human evolutionary history, including the move out of Africa.

　　The research team plans to make the family tree map more comprehensive by continuing to integrate the available genetic data.

Because tree sequences store data in an efficient manner, the dataset can easily accommodate millions of additional genomes.

　　Editor-in-Chief

　　This is the basis of next-generation DNA sequencing.

As the quality of genome sequences in modern and ancient DNA samples improves, tree sequences are becoming more accurate, and ultimately scientists are able to generate a single, unified map that explains all of the human genetic variation we see today.

On the other hand, while humans were the focus of this study, the method worked for most organisms -- from gorillas to small bacteria.

It will also play a role in medical genetics, "pulling" the true associations between genetic regions and diseases from the common ancestral history of mankind.