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In 1924, a three-year-old child's skull found in South Africa forever changed how people think about human origins.

The , our first encounter with an ancient group of proto-humans or called , was a turning point in the study of human evolution. This discovery shifted the focus of human origins research from Europe and Asia onto Africa, setting the stage for the last century of research on the continent and into its " of ."

Few people back then would've been able to predict what scientists know about evolution today, and now . Even since the turn of the 21st century, human origins textbooks have been rewritten over and over again. Just 20 years ago, no one could have imagined what scientists know two decades later about humanity's deep past, let alone how much knowledge could be extracted from a thimble of dirt, a scrape of dental plaque or satellites in space.

Human fossils are outgrowing the family tree

In Africa, there are now dated to between 5 and 7 million years ago, when we know humans likely split off from other Great Apes based on differences in our DNA.

Although discovered in the 1990s, publication of the 4.4 million year old skeleton nicknamed "" in 2009 .

Rounding out our new relatives are a few australopithecines, including Australopithecus deryiremeda and , as well as a potentially late-surviving species of early Homo that reignited debate about when humans first began .

Perspectives on our own species have also changed. Archaeologists previously thought Homo sapiens , but . have pushed that date back to 300,000 years ago, consistent with ancient DNA evidence. This .

This century has also brought unexpected discoveries from Europe and Asia. From enigmatic "hobbits" on the Indonesian island of Flores to the Denisovans in Siberia, our ancestors may have encountered a variety of other hominins when they spread out of Africa. Just this year, researchers reported a .

Anthropologists are realizing that our Homo sapiens ancestors had than previously thought. Today, human evolution and more like a .

Ancient DNA reveals old relationships

Many recent discoveries have been made possible by the .

Since scientists fully sequenced the in 2010, data from have shed new insights on our species' origins and early history.

One shocking discovery is that , modern humans and Neanderthals during the last Ice Age. This is why many people today possess some Neanderthal DNA.

Ancient DNA is how researchers first identified the , who interbred with us . And while most studies are still conducted on bones and teeth, it is now possible to extract ancient DNA from other sources like and .

Genetic methods are also reconstructing and , and connecting ancient individuals to living peoples to end .

The applications go far beyond humans. Paleogenomics is yielding surprising discoveries about and from hidden in the backrooms of museums.

Biomolecules are making the invisible visible

DNA is not the only molecule revolutionizing studies of the past.

, the study of , can and recently linked a 9-foot tall, 1,300-pound extinct ape that lived nearly 2 million years ago to today's orangutans.

Dental calculus—the hardened plaque that your dentist scrapes off your teeth—is particularly informative, revealing everything from to the surprising diversity of plants, some , in Neanderthal diets. Calculus can help scientists understand and how the human . Researchers even find cultural clues—bright blue lapis lazuli trapped in a medieval nun's calculus led historians to reconsider who penned illuminated manuscripts.

Lipid residues trapped in pottery have revealed the and showed that oddly shaped pots found throughout Bronze and Iron Age Europe were ancient baby bottles.

Researchers use of different animal species to answer questions ranging from when to what or even to detect on a page.

Big data is revealing big patterns

While biomolecules help researchers zoom into microscopic detail, other approaches let them zoom out. Archaeologists have used since the 1930s, but widely available now enables researchers to and . Drones flying over sites help and .

Originally developed for space applications, scientists now use LIDAR—a remote sensing technique that uses lasers to measure distance—to map 3-D surfaces and visualize landscapes here on Earth. As a result, ancient cities are emerging from dense vegetation in places like , and South Africa.

Technologies that can peer underground from the surface, such as Ground Penetrating Radar, are also revolutionizing the field—for example, . More and more, archaeologists are able to do their work without even digging a hole.

Teams of archaeologists are in new ways to understand large-scale processes. In 2019, over 250 archaeologists pooled their findings to show that humans have altered the planet for thousands of years, for example, with a in China. This echoes the idea that the Anthropocene, the current period defined by human influences on the planet, .

New connections are raising new possibilities

These advances bring researchers together in exciting new ways. Over , ancient images carved into a Peruvian desert, were discovered using artificial intelligence to sift through drone and satellite imagery. With the wealth of high-resolution satellite imagery online, teams are also turning to to find new archaeological sites.

Although new partnerships among archaeologists and scientific specialists are not always tension-free, there is growing consensus that studying the past means reaching across fields.

The aims to makes this work accessible to all. including are sharing data more freely within and beyond the academy. programs, community digs and digital museum collections are becoming common. You can even print your own copy of famous fossils from , or an in more than 30 languages.

Efforts to make and museums more equitable and engage are gaining momentum as archaeologists consider . Telling the human story requires a community of voices to do things right.

Studying the past to change our present

As new methods enable profound insight into humanity's shared history, a challenge is to ensure that these insights are relevant and beneficial in the present and future.

In a year marked by and , it may seem counterproductive to look back in time.

Yet in so doing, archaeologists are providing empirical support for climate change and revealing how ancient peoples coped with challenging environments.

As one example, studies show that while industrial meat production has , —a traditional practice of seasonally moving livestock, now —is not only today, but helped promote in the past.

Archaeologists today are contributing their methods, data and perspectives toward a vision for a less damaged, more just planet. While it's difficult to predict exactly what the next century holds in terms of archaeological discoveries, a new focus on "" points in a positive direction.

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