What follows is an article published in the Daily Telegraph about the origins of man:
The search for the origins of mankind leads here: 19.4N, 33.7E
Oxford scientists trace roots of ‘vast family tree’ to a dusty corner of Sudan that may be the ancestral homeland of everyone alive today
BySarah Knapton, SCIENCE EDITOR24 February 2022 • 9:56pm
It is an unassuming patch of desert, about 250 miles north of Khartoum in Sudan, but it may be the ancestral homeland of everyone alive today.
Scientists at the University of Oxford have applied computer modelling to thousands of ancient and modern genomes to create a vast family tree showing how individuals across the world are related to each other, and from where they originated.
It suggests that everyone is partially related to a group of hominids who lived in north-east Africa more than a million years ago. It even points to a grid reference: 19.4N, 33.7E, a small area of Sudan.
“The very earliest ancestors we identify do indeed trace back in time to a geographic location that is in modern Sudan,” said Dr Anthony Wilder Wohns, the study’s lead author, who undertook the research as part of his PhD in Oxford and is now at the Broad Institute of MIT and Harvard University.
“These ancestors lived up to and over one million years ago – which is much older than current estimates for the age of modern humans – so bits of our genome have been inherited from individuals that we wouldn’t recognise as modern humans, but who most likely lived in north-east Africa.
“Essentially, we are reconstructing the genomes of our ancestors and using them to form a vast network of relationships. We can then estimate when and where these ancestors lived.”
Network of nearly 27 million predecessors
Researchers said there is some uncertainty about the exact location because of sampling bias, which means that certain areas are not represented. However, they said the findings are compatible with early modern human fossils from eastern and northern Africa.
“At any point in the past we would have had very large numbers of genetic ancestors,” added Dr Yan Wong, an evolutionary geneticist at Oxford’s Big Data Institute.
“The ones that our method locates at the oldest times happen to primarily live in NE Africa, but there are likely to have been others scattered over that continent, which our approach is not powerful enough to pinpoint.”
The earliest evidence of ancient hominids comes from South Africa. However, Kenya’s Rift Valley and Botswana have all been suggested as locations for the birthplace of humans.
Researchers plan to add more genomes to the database as they become available, which will help to give a more accurate location of where the ancestors of humans originated.
“It is likely that if we had more comprehensive sampling of modern and ancient genomes within Africa, the estimated locations of our earliest genetic ancestors would change,” added Dr Wilder Wohns.
‘A genealogy for all of humanity’
To create the family tree, researchers took 6,500 modern and ancient genomes from more than 215 different human populations and used computer power to work out how they were linked, and the timing of genetic changes.
The algorithms predicted where common ancestors must have been present in evolutionary trees, eventually leading to a network which contained almost 27 million predecessors.
After adding location data on these sample genomes, the authors were able to estimate where the ancestors had lived.
The results successfully recaptured key events in human evolutionary history, including the migration out of Africa and when the Americas were first inhabited. However, the team hopes that when more genomes are added, it will start to show ancient human movements which have been lost in time.
Dr Wong said: “We have basically built a huge family tree, a genealogy for all of humanity that models as exactly as we can the history that generated all the genetic variation we find in humans today.
“This genealogy allows us to see how every person’s genetic sequence relates to every other. This study is laying the groundwork for the next generation of DNA sequencing.
“As the quality of genome sequences from modern and ancient DNA samples improves, the trees will become even more accurate and we will eventually be able to generate a single, unified map that explains the descent of all the human genetic variation we see today.”
The research has been published in the journal Science.