Recently, we have learned that humanity has few genetic variations and this could jeopardize the future of human beings. However, it is important to understand how men and women have evolved throughout their history. Thus, researchers from the University of Oxford have created the largest human family tree ever created.
It’s amazing how connected people all over the world are to each other. And the results of the study give us unprecedented detail.
What if your ancestors came from prehistory?
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 across the world relate to one another.
Until now, the main challenges of this vision were to discover a technique to combine genomic sequences from many different databases and to develop algorithms to process data of this size. However, a new method now published by researchers at the University of Oxford’s Big Data Institute can easily combine data from multiple sources and scale to millions of genomic sequences.
Basically, we’re building a huge family tree, a genealogy for all of humanity that models exactly how we can the history that generated all of the genetic variation that we find in humans today. This genealogy allows us to see how each person’s genetic sequence relates to all others, across all points of the genome.
Explained Yan Wong, evolutionary geneticist at the Big Data Institute and leading author.
As the study points out, individual genomic regions are inherited from a single parent, either mother or father, the ancestry of each point in the genome can be thought of as a tree. The set of trees, known as a “tree sequence” or “ancestral recombination graph”, links the genetic regions in time to the ancestors where the genetic variation first appeared.
DNA does not lie
The study integrated data on modern and ancient human genomes from eight different databases and included a total of 3,609 individual genomic sequences from 215 populations. The ancient genomes included samples found all over the world ranging in age from 1,000 to over 100,000 years.
Algorithms predicted where common ancestors must be present in evolutionary trees to explain patterns of genetic variation. The resulting network contained nearly 27 million ancestors.
After adding location data to these genome samples, the authors used the network to estimate where the predicted common ancestors lived. The results successfully captured key events in human evolutionary history, including migration out of Africa.
While the genealogical map is already an extremely rich resource, the research team intends to make it even more complete. To this end, they will continue to integrate genetic data as it becomes available. Since tree sequences store data very efficiently, the dataset can easily accommodate millions of additional genomes.
This study lays the groundwork for the next generation of DNA sequencing. As the quality of genomic sequences from modern and ancient DNA samples improves, the trees will become even more accurate, and we may eventually be able to generate a single, unified map that explains the descent of all human genetic variations that we see today.
Concludes geneticist Yan Wong.
This study, although centered on human beings, could see its method extended to most living beings; from orangutans to bacteria.
Trashtalk – the Greatest Basketball Book of All Time
The greatest detective of all time