A 2022 experience in creating an extensive family tree for the human race and at least three others reaching back 2 million years, long before Homo sapiens believed to have originated in Africa 200,000 years ago.
The study from the Oxford Institute for Big Data was based on 3,601 human genomes taken from several modern databases, eight ancient individuals and 3,589 more ancient samples obtained from 100 other studies. Using specialized algorithms, the researchers shaped the tree further by adding limbs until they reached about 27 million ancestors.
Human family tree
The result was stretched and imprecise, but as the researchers say in a press release, this is the first tree of more to come. “As the quality of genome sequences from modern and ancient DNA samples improves,” says Yan Wong, an evolutionary geneticist at the Big Data Institute, “the trees will become even more accurate, and eventually we will be able to generate a single, unified map that explains the origin of all human genetic variation we see today.
According to the first tree, early humans originated in Sudan about 2 million years ago and moved to the Middle East and Central Asia only about 280,000 years ago. Then, about 140,000 years ago, a concentration formed in Papua New Guinea in Oceania.
The researchers found that modern Oceania (the region east of Southeast Asia) contains the most residual genes from the ancient Denisovan people, an early human group that walked the soils of Asia and Oceania long before Homo sapiens. The area of Papua New Guinea also carries significant signs of Neanderthal DNA, along with much of Asia and Siberia.
The study also concluded that early humans settled in Central and South America about 56,000 years ago, much earlier than previous estimates, a possible artifact caused by later descendants who lived in the area. A 2016 study estimates that humans first traveled from the Alaskan region to what is now the Pacific Northwest about 16,000 years ago.
Our Ancestors: A Tree of Human Evolution
About 700,000 years ago, the ape-like Homo erectus, emigrated from Africa and split (after 100,000 years) into Neanderthals and Denisovans, scientists believe. For reasons discussed, Neanderthals evolved west of the Himalayan mountains, roughly speaking, and Denisovans to the east. Sometimes the Neanderthals mated with Denisovansboth species later mate with Homo sapiens when we migrated from Africa.
Neanderthals had short, stocky bodies with long arms, prominent eyebrows and large noses. The elusive Denisovans, who left behind meager archaeological records, had flatter faces and, like Neanderthals, stocky figures. Homo erectus probably resembled a cartoonish caveman with an elongated skull and prominent brow ridge, which may or may not have served a purpose.
The scientists included three Neanderthal genomes in the tree and one Denisovan, which previous researchers found that they contained slightly more ape-like genes than modern humans.
The tree model introduced by the Big Data study can be applied to more than just humans, according to Anthony Wilder Vance, a researcher at the Big Data Institute and lead author of the tree study. “The method is valid for most living things, from orangutans to bacteria.”