Science is revolutionizing our understanding of the past.
Paleogenetics unravels amazing secrets from DNA hidden in bones and dirt. Artificial intelligence decodes ancient texts written in forgotten scripts. Chemical analysis of molecular residues left behind on teeth, cooking pots, incense burners and building materials reveals details about past diets, odors and construction techniques.
Here are six mysteries about human history that scientists have solved in 2023. Plus a mystery that researchers are still wondering about.
The true identity of a prehistoric leader
Buried with a spectacular crystal dagger and other priceless artifacts, the 5,000-year-old skeleton discovered in 2008 in a tomb near Seville, Spain, was clearly once someone important.
It was initially thought to be a young man, based on analysis of the pelvic bone, the traditional way scientists determine the gender of human skeletal remains.
However, an analysis of tooth enamel, which contains a type of protein with a gender-specific peptide called amelogenin, revealed that the remains were female rather than male.
In other studies, the technique has also dispelled the cliché of "man the hunter" that fueled much thinking about early humans.
"We think this technique will open a completely new era in the analysis of the social organization of prehistoric societies," Leonardo García Sanjuán, professor of prehistory at the University of Seville, told CNN in July when the discovery was made. made public.
The ingredient behind the legendary strength of Roman concrete
Roman concrete has proven to have a longer lifespan than its modern equivalent, which can deteriorate within decades. Take for example the Pantheon in Rome, which has the largest unreinforced dome in the world.
Scientists behind a study published in January said they had discovered the mysterious ingredient that allowed the Romans to make their building materials so durable and build complicated structures in challenging places such as docks, sewers and earthquake zones.
The story continues
The research team analyzed 2,000-year-old concrete samples taken from a city wall at the Privernum archaeological site in central Italy, which are similar in composition to other concrete found throughout the Roman Empire.
They found that white chunks in the concrete, called limestones, gave the concrete the ability to heal cracks that had formed over time. The white chunks were previously overlooked as evidence of sloppy mixing or poor quality raw materials.
The actual appearance of Ötzi the iceman
Hikers found Ötzi's mummified body in 1991 in a gully high in the Italian Alps. Its frozen remains are perhaps the most studied archaeological find in the world, revealing in unprecedented detail what life was like 5,300 years ago.
His stomach contents have provided information about what his last meal was and where he came from, while his weapons revealed that he was right-handed, and his clothing provided a rare glimpse into what ancient people actually wore.
But a new analysis of DNA from Ötzi's pelvis revealed in August that his physical appearance was not what scientists first thought.
Research into his genetic makeup showed that Ötzi the Iceman had dark skin and eyes - and was probably bald. This revised appearance is in stark contrast to Ötzi's well-known reconstruction, which depicts a man with pale skin, a full head of hair and a beard.
The bearer of the 20,000-year-old pendant revealed
Archaeologists regularly dig up bone tools and other artifacts from ancient sites, but it's impossible to know for sure who ever used or wore them.
Earlier this year, scientists recovered ancient human DNA from a pendant made from deer bone found in Denisova Cave in Siberia. With that clue, they were able to reveal that its bearer was a woman who lived between 19,000 and 25,000 years ago.
She belonged to a group known as Ancient North Eurasians, which has a genetic link to the first Americans.
Human DNA is likely preserved in the deer bone pendant because it is porous and therefore more likely to retain genetic material present in skin cells, sweat and other bodily fluids.
It is not known why the deer tooth pendant contained such a large amount of the ancient woman's DNA (about the same amount as a human tooth). Perhaps it was much loved and worn close to the skin for an exceptionally long time, says Elena Essel, a molecular biologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who developed a new technique to extract the DNA.
The ancient, damaged scroll decoded by AI
During the famous eruption of Mount Vesuvius almost 2,000 years ago, some 1,100 scrolls were burned. In the 18th century, some enterprising diggers recovered the enormous cache from volcanic mud.
The collection, known as the Herculaneum Scrolls, is perhaps the largest known library from classical antiquity, but the contents of the fragile documents remained a mystery until a computer science student at the University of Nebraska won a scientific competition earlier this year.
Using artificial intelligence and computed tomography imaging, Luke Farritor was the first to decode a word in Ancient Greek on one of those blackened scrolls.
Farritor received $40,000 for deciphering the word 'πορφυρας' or 'porphyras', the Greek word for purple. Researchers hope that it won't be long before entire scrolls can be deciphered using this technique.
The materials needed to make a mummy
From fragments of discarded jars in an embalming workshop, scientists have discovered some of the substances and concoctions that the ancient Egyptians used to mummify the dead.
By chemically analyzing the organic remains left in the vessels, researchers determined that the ancient Egyptians used a wide variety of substances to anoint the body after death, reduce unpleasant odors and protect it from mold, bacteria and putrefaction. Identified materials include vegetable oils such as juniper, cypress and cedar, as well as pistachio tree resins, animal fat and beeswax.
Although scholars had previously learned the names of substances used to embalm the dead from Egyptian texts, they could - until recently - only guess at exactly what substances and materials they referred to.
The ingredients used in the workshop were varied and came not only from Egypt but much further afield, indicating the exchange of goods over long distances.
Beethoven: A family secret revealed, but one mystery remains
Composer Ludwig van Beethoven died in 1827 at the age of 56 after a series of chronic health problems, including hearing loss, gastrointestinal problems and liver disease.
Beethoven wrote a letter to his brothers in 1802 asking his physician, Johann Adam Schmidt, to investigate the nature of the composer's illnesses after he died. The letter is known as the Heiligenstadt Testament.
Nearly 200 years after his death, scientists extracted DNA from preserved strands of hair in an attempt to fulfill this request.
Ashley Strickland and Taylor Nicioli contributed to this report.The team couldn't make a definitive diagnosis, but Beethoven's genetic data helped researchers rule out possible causes of his condition, such as the autoimmune disease celiac disease, lactose intolerance or irritable bowel syndrome.
The genetic information also suggested that an extramarital affair had taken place in the composer's family.
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