Earliest Evidence of Our Human Ancestors Outside of Africa Found

Artifact excavated from a layer that is 2.1 million years old. The artifact here is a stone from which three flakes were removed.

Credit: Zhaoyu Zhu

In earlier posts I have looked at the origin and spread of modern humans. New discoveries have led to the reappraisal of migration dates and routes as well as a greater understanding of our early ancestors. Undoubtedly, this picture will continue to change and it is difficult keeping pace with the latest thinking on the subject.

A recent article on the website ‘Live Science’ reported that researchers in China had excavated stone tools that were likely made by our human ancestors some 2.12 million years ago. This is the earliest evidence found so far of our human ancestors outside of Africa.

Archaeologists from China and the United Kingdom discovered dozens of quartz and quartzite stones at Shangchen, China, on what is known as the Loess Plateau. The site contains several layers of loess, which is fine, windblown sediment dating from 1.26 million to 2.12 million years ago.

Hominins, which may have originated in Africa up to 6 million years ago, include all the species that emerged after the Homo genus, split from that of chimpanzees. Until now, the earliest evidence of hominins outside of Africa came from a skeleton and artefacts linked to Homo erectus and dating to 1.85 million years ago found in the Republic of Georgia, in 2000. Humans and chimpanzees are very closely related and separated about 7.4 million years ago.  There is only a 1% difference between the chimpanzee genome and our own suggesting that we have a common ancestor.

Among the artefacts excavated was a stone, from which three flakes were removed, found in a layer that is 2.1 million years old. Paleoanthropologists are excited about the finds because you don't often find artefacts in their original context. Researchers noticed how the flaking of the stones was repeated to create lines in various directions.

Robin Dennell, a paleoanthropologist at the University of Exeter, pointing out that the Loess Plateau is a stone-free landscape, states:

"There are no natural processes that could have flaked these items, so you know that any flaked object could only have been flaked by an early human."

The presence of these stone tools suggests that human ancestors left Arica roughly 10,000 generations earlier than previously thought. However, experts don’t know for sure what species of hominin made the tools. It is possible that these ancient stone tools were made by Homo erectus, but they could have been made by an even earlier ancestor.

For further information please see:

https://www.livescience.com/63033-earliest-hominin-china.html?utm_source=notification

https://www.youtube.com/watch?v=3wmYwbuadvw

Ötzi the Iceman Was a Heart Attack Waiting to Happen

Ötzi the iceman

Some time ago I wrote a post about Ötzi the iceman. The website, Live Science (30^th May 2018) recently featured an article updating readers on the iceman’s health based on recent analysis of Ötzi’s mummified body.

Ötzi was murdered about 5,300 years ago high in the Italian Alps. His mummified body was discovered by hikers in 1991 and he is now housed at the South Tyrol Museum of Archaeology in Bolzano, Italy. He was shot with an arrow, struck on the head, and left to die near a mountain pass high in the Alps.

Ötzi's health

Further analysis of Ötzi’s body reveal that he didn’t ‘enjoy’ good health and had an unhealthy diet. A full-body computed tomography (CT) scan showed that he had three calcifications (hardened plaques) in his heart region, putting him at increased risk for a heart attack. A modern heart doctor would have encouraged him to stop eating fatty meat and to take medication to lower his blood pressure and cholesterol.

He also had calcifications around his carotid artery, which carries blood to the head and neck, and in the arteries at the base of his skull, which carry blood to the brain. These conditions increased the iceman’s risk of a stroke. In an earlier study, researchers found that Ötzi's last meal included the fatty meat of a wild goat, as well as wild deer and grains. Today, Ötzi may have undergone surgery to help prevent a stroke including, perhaps, coronary bypass surgery, to divert blood flow around the blocked artery.

Statue of Ötzi the iceman

The iceman is one of the most studied mummies in the world. Researchers know that he had bad teeth and knees; lactose intolerance; a probable case of Lyme disease; stomach bacteria that causes ulcers; and 61 tattoos inked on his body. The latest findings suggest that if Ötzi hadn't been killed by a blow to the head and an arrow that pierced his shoulder when he was about 46 years old, he might have suffered health problems from these conditions later in life.

Genetic Factors

An earlier study found that Ötzi had a genetic predisposition for atherosclerosis, a narrowing of the arteries from fatty deposits. CT scans done at the time showed signs of disease in some of his arteries. Ötzi wasn't overweight, didn't smoke tobacco, regularly exercised and was unlikely to have had a high-fat diet. Researchers believe that genetic factors, rather than his daily routine, may explain his health condition.

In the new study, the researchers examined a newer CT scan of Ötzi that was done in 2013 using a larger CT scanner. This enabled them to image Ötzi's entire body, including his abdomen and chest, allowing them to pinpoint the hardened plaques.

Timeline of Ötzi's last hours

Ötzi wasn't far from home when he died. Scientists concluded that he didn't live in the Alps as such but spent most of his life in Isack Valley or the lower Puster Valley, in the northernmost part of what is now Italy. He probably spent the last 10 years of his life in an area south and west of his previous home, not far from where he died.

Conclusion

The iceman was murdered high up in the Italian Alps some 5,300 years ago, making his death the oldest unsolved ‘cold case’ crime. Although Ötzi died in his mid-forties, he may not have lived to a ‘ripe old age’. Genetic factors rather than lifestyle may have increased his risk of a heart attack and stroke.

For further information see:

https://www.livescience.com/62689-otzi-iceman-mummy-heart-disease.html

http://letterfromballinloughane.blogspot.com/2017/12/otzi-iceman.html

Videos

https://www.youtube.com/watch?v=bZr-uAOJqo4

https://www.youtube.com/watch?v=nk261CZaCKg

https://www.youtube.com/watch?v=bZr-uAOJqo4&t=32s