An ancient stone tool unearthed at the excavation site near Kenya's Lake Turkana. It's not just the shape and sharp edges that suggest it was deliberately crafted, the researchers say, but also the dozens of stone flakes next to it that were part of the same kit. MPK-WTAP hide caption

itoggle caption MPK-WTAP

Buddhist monks recover a statue of a Buddhist deity from a monastery at Swayambhunath. Niranjan Shrestha/AP hide caption

itoggle caption Niranjan Shrestha/AP

Dura Europos, a Roman walled city in eastern Syria, dates back to 330 B.C. The main gate is shown here in a photo from 2010. It's one of the many important archaeological sites militants of the self-styled Islamic State have ransacked and damaged. EPA /Deir Ezz-Zour Antiquities Department/Landov hide caption

itoggle caption EPA /Deir Ezz-Zour Antiquities Department/Landov

A view of part of the vast Mosquitia jungle in Honduras. A team of explorers, guided by scans made from airplanes, recently discovered an important ancient city in the region. Courtesy of UTL Productions hide caption

itoggle caption Courtesy of UTL Productions

With the help of researcher Sabudo Boraru (right), anthropologist Chris Campisano, of Arizona State University, takes samples from the fossil-filled Ledi-Geraru project area in Ethiopia. The jawbone was found nearby. Courtesy of J Ramón Arrowsmith hide caption

itoggle caption Courtesy of J Ramón Arrowsmith

Then-U.S. ambassador to Iraq Christopher Hill (right) tours the Mosul Museum of History in May 2009. This week the self-declared Islamic State posted a video online that showed militants going through the museum, pushing over statues and smashing artifacts with sledgehammers. Mujahed Mohammed/AFP/Getty Images hide caption

itoggle caption Mujahed Mohammed/AFP/Getty Images

Students Patrick Rohrer, Sarah Warthen, Alix Piven and Lauren Urane are led by Mercyhurst University Archeologist Andy Hemmings. Their project has picked up where Florida's State Geologist Elias Sellards left off in 1915. Sellards led an excavation of the site where workers digging a drainage canal found fossilized human remains. Greg Allen/NPR hide caption

itoggle caption Greg Allen/NPR

A field of unharvested wheat is seen in Ashby-de-la-Zouch, England, in 2012. Wheat wasn't cultivated in Britain until some 6,000 years ago, but DNA evidence suggests early Britons were eating the grain at least 8,000 years ago. Darren Staples/Reuters/Landov hide caption

itoggle caption Darren Staples/Reuters/Landov

An illustration depicts Jesus Christ transforming water into wine during the wedding at Cana (John 2:7). Joseph Martin Kronheim/Kean Collection/Getty Images hide caption

itoggle caption Joseph Martin Kronheim/Kean Collection/Getty Images

An Israeli Antiquities Authority Prevention of Antiquities Robbery officer stands at the opening to a high cave in the Judean desert. Six men were indicted Sunday for looting from this cave. Israel Antiquities Authority hide caption

itoggle caption Israel Antiquities Authority

The site at Gobekli Tepe, or "Potbelly Hill," on the Urfa plain in southeastern Turkey is believed by some to be the world's first place of worship. This would upend the conventional thought that religion developed as a byproduct of human settlements. Vincent J. Musi/National Geographic Society/Corbis hide caption

itoggle caption Vincent J. Musi/National Geographic Society/Corbis

A stencil of an early human's hand in an Indonesian cave is estimated to be about 39,000 years old. Kinza Riza/Courtesy of Nature.com hide caption

itoggle caption Kinza Riza/Courtesy of Nature.com

Archaeologists inspect a female figurine inside a recently discovered, fourth-century B.C. tomb, in the town of Amphipolis, northern Greece on Sept. 7. The occupant of the tomb is unknown, but there's speculation that it could be someone who was closely linked to Alexander the Great. Greek Culture Ministry/AP hide caption

itoggle caption Greek Culture Ministry/AP