Scientists Create World’s Largest Family Tree Connecting 27 MILLION People

Scientists have created the “world’s largest family tree” that connects around 27 million people around the world – living and dead.

Developed at the University of Oxford, the new genealogy network reveals how individuals around the world are linked to each other in “unprecedented detail”.

Taking the form of a scientific method, research paper, and video, it effectively goes back in time to show where human populations lived and when.

The earliest ancestors, which predate Homo sapiens, date back in time to a geographic location in modern-day Sudan, likely over a million years ago.

This image visualizes inferred human ancestral lines in time and space. Each lineage represents an ancestor-descendant relationship in our “inferred genealogy from modern and ancient genomes”. The width of a line corresponds to the number of times the relationship is observed, and the lines are colored according to the estimated age of the ancestor

WHAT IS A GENOME?

Your genome is the instructions for making and sustaining you. It is written in a chemical code called DNA. All living things – plants, bacteria, viruses and animals – have a genome.

Your genome is all 3.2 billion letters of your DNA. It contains about 20,000 genes.

Genes are the instructions for making the proteins our bodies are made of – from the keratin in hair and nails to antibody proteins that fight infection.

Source: Genomics England

The project was published today in the journal Science by researchers at the Big Data Institute at the University of Oxford.

“We have essentially built a huge family tree, a genealogy for all of humanity that models as accurately as possible the history that generated all the genetic variations that we find in humans today,” said Dr Yan Wong. , study author and evolutionary geneticist.

“This genealogy allows us to see how each person’s genetic sequence is related to the other, along all points of the genome.

“While humans are the focus of this study, the method is valid for most living things; from orangutans to bacteria. This could be particularly beneficial in medical genetics, separating true associations between genetic regions and diseases from false connections stemming from our shared ancestral history.

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 possibility of tracing the origins of human genetic diversity to produce a comprehensive map of how individuals across the world relate to each other, the team says.

Two-dimensional histograms showing the geographic location of ancestral lineages at six points in time.  1 kya is the abbreviation for thousand years ago

Two-dimensional histograms showing the geographic location of ancestral lineages at six points in time. 1 kya is the abbreviation for thousand years ago

FAMILY TREE

Since individual genomic regions are inherited from only one parent, either mother or father, the ancestry of each point in the genome can be considered as a tree.

The set of trees, known as a “tree sequence” or “ancestral recombination graph,” links genetic regions through time to the ancestors where the genetic variation first appeared.

Until now, researchers have struggled to find a way to combine genome sequences from many different databases and develop algorithms to handle data of this size.

However, the new method can easily combine data from multiple sources and scale to millions of genomic sequences.

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 across the globe with ages ranging from 1,000 to over 100,000 years.

“Essentially, we reconstruct the genomes of our ancestors and use them to form a vast web of relationships,” said lead author Dr. Anthony Wilder Wohns, now a postdoctoral fellow at MIT’s Broad Institute and Harvard.

“We can then estimate when and where these ancestors lived. The power of our approach is that it makes very few assumptions about the underlying data and can also include modern and ancient DNA samples.

About 2,000 years ago, humans were well distributed throughout the world, except for much of North America, Oceania, and other places.

About 2,000 years ago, humans were well distributed throughout the world, except for much of North America, Oceania, and other places.

But over 300,000 years ago humans were more centered in Africa, animation shows

But over 300,000 years ago humans were more centered in Africa, animation shows

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 had lived.

The results successfully captured key events in human evolutionary history, including migration out of Africa.

The very first ancestors identified by the team were “most likely” Homo erectus, an extinct species of archaic human, which dates back in time to a geographic location that is in modern-day Sudan.

Dr Yan Wong and Dr Wohns said in a joint statement: “These ancestors lived until over a million years ago – which is much older than current estimates of the age of the modern humans (about 250,000 to 300,000 years ago) – so pieces of our genome were inherited from individuals we wouldn’t recognize as modern humans, but most likely lived in northeast Africa .

“It is very likely that these very ancient ancestors were Homo erectus, but we cannot be sure of their identity or whereabouts without extremely ancient DNA.

“An important finding of our work is that the people we often refer to as the ‘cradle of humanity’ themselves had ancestors more distant in time, whose descendants are still with us today.”

WHAT DO WE KNOW ABOUT HUMANITY’S JOURNEY OUT OF AFRICA?

The traditional view

The traditional “Out of Africa” ​​model suggests that modern humans evolved in Africa and then left in a single wave around 60,000 years ago.

The pattern often holds once modern humans left the continent a brief period of interbreeding with Neanderthals occurred.

This explains why individuals of European and Asian descent still have ancient human DNA today.

There are many theories about what led to the downfall of the Neanderthals.

Experts have suggested that early humans may have brought with them tropical diseases from Africa that wiped out their ape-like cousins.

Others claim that falling temperatures due to climate change wiped out the Neanderthals.

The prevailing theory is that early humans killed Neanderthals through competition for food and habitat.

How the story changes in light of new research

Recent findings suggest that the “Out of Africa” theory does not tell the full story of our ancestors.

Instead, multiple, smaller movements of humans out of Africa beginning 120,000 years ago were then followed by a major migration 60,000 years ago.

Most of our DNA is made up of this latter group, but earlier migrations, also known as “scatters,” are still evident.

This explains recent studies of the earliest human remains found in the far reaches of Asia dating back over 60,000 years.

For example, remains of H. sapiens have been found at several sites in southern and central China dated between 70,000 and 120,000 years ago.

Other recent discoveries show that modern humans reached Southeast Asia and Australia 60,000 years ago.

Based on these studies, humans could not have come in a single wave from Africa at this time, according to studies.

Instead, the origin of man suggests that modern humans developed in multiple regions of the world.

The theory claims that pre-human ancestor groups left Africa and spread to parts of Europe and the Middle East.

From there, the species evolved into modern humans in several places at once.

The argument rests on a new analysis of a 260,000-year-old skull found in Dali County, China’s Shaanxi Province.

The skull suggests that early humans migrated to Asia, where they developed modern human features, and then returned to Africa.

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