A 1.5 million year old fossil is rewriting the “Out of Africa” theory once again, as vertebrae unearthed in Ubeidiya, Israel appear to show that individuals from a pre-human species came in one of multiple waves out of the vast continent.
The history of humanity involves many migrations out of Africa, made for different reasons, with varying levels of evolution evident in each group. Scientists now believe that there were multiple migrations out of the continent before modern Homo sapiens migrated out approximately 270,000 years ago, mixing with Neanderthals who were already living in Europe and Asia, along with Denisovans.
Individuals from human species that are now extinct have been shown to have migrated from Africa to Eurasia by at least 1.8 million years ago, during the early Pleistocene era, which was from 2.6 million to 11,700 years ago.
This vast span of time includes the last Ice Age, which involved so much sea water being absorbed into ice that there were land bridges between what is now Siberia and Alaska and the European continent and the UK.
Although modern humans are currently the only surviving member of our long human lineage, other human species have traveled far and wide, exploring most of the Earth’s continents far back into antiquity.
Newly analyzed vertebrae of an unknown human species have been unearthed in Israel at what is believed to be the second-oldest archaeological site outside of Africa, supporting the theory that there were indeed many waves of humans leaving Africa for millions of years.
Dating back about 1.5 million years, the vertebrae found at ‘Ubeidiya, located in the Jordan Valley, are the oldest evidence ever found of any ancient people in Israel, according to Alon Barash, the Paleontology and Human Anatomy at the University of Bar-Ilan in Israel.
In an interview with Live Science, Barash, who published his findings in February in the journal Scientific Reports, said that the site has brought to light not only ancient stone artifacts like objects found in East Africa but also a patch of extinct species such as saber-toothed cats and mammoths as well.
Back in 2018, scientists re-examined a vertebra from the lower back of hominins, a group that includes humans, whose ancestors were our closest evolutionary ancestors. The skeletons, originally unearthed at ‘Ubeidiya in 1966, have undergone a complex new analysis that allows their exact age to be determined.
John Hawks, a paleontologist at the University of Wisconsin-Madison who was not involved in the study, told interviewers from Live Science that “It’s great to see new discoveries coming from old collections like this one. It shows that there is always something left to find even when archaeologists think they’ve done it all.”
Although there isn’t enough data from this one bone to show with certainty that it belonged to any extinct human species, after researchers compared the vertebra to those of animals, including bears, hyenas, hippos, rhinos, horses, gorillas and chimpanzees. , all of which lived in the area at the same time, the team concluded that it came from an extinct human species.
Intriguingly, although the scientists say that, given the bone’s size, shape and other properties, the researchers estimated it was from a child aged from 6 to 12 years, but he or she would have been about 5 feet, 1 inch (155 centimeters) tall, weighing about 100 to 110 pounds (45 to 50 kilograms). Since this is the size of an average 11- to 15-year-old modern human, this means the child would have towered over his modern human contemporaries.
In other words, this child would be head and shoulders taller than his modern children.
“The study shows how much information about an ancient individual we can get from a small piece of the anatomy,” notes Hawks.
The find alone precedes much of previous research on human ancestors on its head, with most species being small in size until relatively recent in human history.
About 1.8 million years old human fossil unearthed in Dmanisi, Georgia, shows that the extinct human species whose remains were found there were of small stature, ranging from 4 feet, 9 inches to 5 feet tall, 5 inches (145 to 166 cm) and weighs 88 to 110 pounds (40 to 50 kg) as an adult.
The Israeli scientists analyzing the vertebra found at ‘Ubeidiya believe that in adulthood, that individual may have outstripped the majority of modern humans in size and heft, growing to reach 6 feet, 6 inches (198 cm) in height and weighing 220 pounds (100 kg).
“Dmanisi hominins are small in body size — at the smallest end of human variation across populations today,” Hawks explained, adding “This new vertebral body suggests a large body size, like some of those seen in Africa at around the same time.”
Scientists say the discovery shows a 1.8-million-year-old fossil from Dmanisi and a 1.5-million-year-old vertebra from ‘Ubeidiya’ as evidence of two different types of hominins. That means ancient humans most likely left Africa in waves.
“We can securely talk about two early Pleistocene out-of-Africa migration waves,” Barash noted in the interview.
Other differences were found between artifacts at both sites, the researchers said, adding to the growing body of evidence that these peoples belonged to different groups of people. The types of stone tools found at Dmanisi, known as Oldowan, were fairly basic, usually made from one or more chipped, or hewn, pieces of stone left by another.
But Israeli stone tools, of the early Acheulean type, were more complex, including hand axes made from volcanic rock, Live Science reported.
And in contrast to their present climate, the Dmanisi were drier and steppe-like, and the ‘Ubeidiya at that time were warmer and wetter, even part of a woodland climate, which made the people living in these areas That location develops different tools to adapt to their different needs.
But the sheer size of this vertebrae found at ‘Ubeidiya’ may pose a problem in itself, leading to some speculation that the person may have contracted some kind of medical problem.
Naturally, this would skew findings regarding the size of different hominid populations, making it “very risky to use as the representative for an entire species,” says Marc Meyer, a paleoanthropologist at Chaffey College in Rancho Cucamonga, California, who was not involved in the study.
“Assuming that it is a hominin, what is mind-blowing is that the ‘Ubeidiya fossil is developmentally like a 5-year-old but is significantly larger than our team’s entire sample of fossil Homo and juvenile humans up to age 17,” he adds.
“In fact, it’s the size of very large individuals such as Neanderthals or gorillas. To have a 5-year-old child as large as an adult gorilla is just wild.”
Hawks says that this may be just another example of natural human genetic variations. “Humans have changed in body size many times in our evolution, and both large-bodied and small-bodied human populations today have emerged over thousands of years, which is a short time compared to the hundreds of thousands of years here,” he said.
And that in itself is not evidence that this ‘Ubeidiya group was of another lineage than that in Georgia.
“I think it’s likely that humans or other hominins were in Eurasia much earlier than Dmanisi,” Hawks said, adding “There are a few sites that seem to have older stone tool evidence, in Jordan, China and Pakistan.”
Barash said that despite these spectacular finds, which represent the oldest evidence ever found of any ancient people in Israel, “we need to continue excavation in ‘Ubeidiya – who knows what bones are waiting to be discovered.”