With the availability of home DNA-test kits, people have been using samples of saliva and cells to search for, among other things, unknown relatives. But that approach will only help you narrow your search back maybe a few generations. Over the past 150 years, many scientists have attempted to hunt down our earliest ancestors — folk who trace to the first emergence of humankind.
Their search hasn’t been easy. Along the way, there have been varied clues — and plenty of stumbles. But many have forged on in a quest that continues to this day.
Charles Darwin was among the earlier scientists to look for the ultimate roots of our family tree. Back in 1871, he hypothesized that humankind’s earliest ancestors must have lived in Africa. His reasoning: Among all animals, the African apes — gorillas and chimpanzees — were most similar to humans. But at the time, there was no fossil evidence to support Darwin’s claim. The few human fossils known had all been found in Europe.
Over the next 50 years, more would trickle in from there and Asia. So had Darwin picked the wrong continent?
No. In 1924, miners in a South African limestone quarry made a surprising find. It was the fossilized skull of a toddler. Based on its features, Raymond Dart concluded this fossil was a fabled “missing link” between humans and apes. Dart was an anatomist at the University of the Witwatersrand in Johannesburg, South Africa. This fossil was the most apelike yet for a hominid — that is, a member of the extended human family. Known as Hominidae, this family includes our species and all of our close, extinct relatives.
That fossil wasn’t enough to confirm Africa as our homeland. But since that first discovery, anthropologists have amassed many thousands more fossils that have pointed to Africa as our place of origin. More recently, genetic studies have reinforced this story.
African apes are indeed our closest living relatives, with chimpanzees most closely related to us. In fact, scientists now include great apes in the hominid family. They use a more restrictive term — hominin — to refer to us and our most closely related extinct cousins.
Genetics show humans likely trace back to Africa
The study of human evolution is a field known for bitter feuds and rivalries. But one concept unifies these scientists: the idea that our roots go back to Africa. “I think everybody agrees and understands that Africa was very pivotal in the evolution of our species,” says Charles Musiba. He’s a paleoanthropologist. He works at the University of Colorado Denver.
Paleoanthropologists have sketched a rough timeline of our evolution. Sometime between 9 million and 6 million years ago, the first hominins emerged. Walking upright on two legs distinguished these ancestors from other apes. Hominins also had smaller canine teeth. That may signal they were less aggressive and more social.
Between about 3.5 million and 3 million years ago, some of our ancestors ventured beyond wooded areas. Africa was growing drier. Grasslands were spreading across the continent. Hominins were now crafting stone tools. Our genus, Homo, arrived by 2 million years ago, maybe earlier. These members of our family had larger brains than their ancestors. By at least 2 million years ago, members of our genus started moving into Eurasia. By about 300,000 years ago, our species — Homo sapiens — had arrived.
You must be logged in to post a comment.