Modern-day humans, scientifically known as Homo sapiens, are the sole living members of the genus Homo. Our human ancestors originated from Africa, and recent studies indicate that humans do not have a singular birthplace but rather originated from a few different populations within the continent.

Homo erectus, one of the early human ancestors, is believed to be the first species of the Homo genus that migrated out of Africa, said Michael Pante, a paleoanthropologist and chair of the department of anthropology and geography at Colorado State University. The migration was originally thought to have happened about 1.8 million years ago, but new evidence found in a study started by Sabrina Curran of Ohio University suggests this migration may have happened nearly 200,000 years earlier than previously thought.

Previously, evidence of the earliest human ancestors in Europe was found in Dmanisi, Georgia, in the form of a skull with features extremely similar to that of Homo erectus in Africa. However, the evidence used in Curran’s study came from a site in Romania. Bones previously found at this site were considered to be strictly of paleontological importance until their recent re-examination by Curran and her team.

“We used both established qualitative methods and quantitative methods that yield high reclassification rates,” Curran said in the publication.

These methods included a 3D quantitative method that was developed and published by Pante in 2017. This method was used to provide objective and quantitative evidence for the study.

Almost 5,000 bones that were previously excavated from a site in Romania, called Grăunceanu, were closely examined. With the use of a 3D quantitative method and database, it was discovered that marks previously considered to be scratches on these fossils are actually cuts made by deliberate human-animal butchery, Pante said.

“No other trace of human ancestors was found at the site, so establishing their presence on butchery marks alone required a much higher level of certainty.” -Michael Pante, CSU department of anthropology and geography chair

“The (3D quantitative) method uses machine learning to compare measurements of marks found on the surface of fossils to a database of nearly 1,000 marks that were experimentally created and of known origin,” Pante said. “Our experimental database includes measurements taken from high-resolution 3D models of marks made by humans, carnivores and even herbivores stepping on bones, the last of which can resemble marks left behind by our ancestors through their use of stone tools to process animals for food.”

The 3D quantitative method Pante developed has been used in several other groundbreaking research studies, including one done in collaboration with the Smithsonian’s National Museum of Natural History that found evidence of early human ancestors engaging in cannibalism.

“The ongoing debate regarding the timing and location of the earliest hominin dispersal(s) into Eurasia has been hampered by a variety of challenges, including dating uncertainty, lack of research in some geographic regions and arguments about the anthropogenic nature of several lithic assemblages,” Curran said in the publication.

Without Pante’s database, it would have been difficult to prove the presence of early human ancestors at the site without other definitive traces, such as remains or tools. The 3D database supplied the study with quantitative data that helped establish certainty of human ancestor presence at the site.

“No other trace of human ancestors was found at the site, so establishing their presence on butchery marks alone required a much higher level of certainty,” Pante said.

This new evidence, supplied in part by Pante and his research, has pushed back the timeline of human ancestors in Europe by roughly 200,000 years. The discovery raises new questions about what other sites might contain evidence of early human ancestors.

Despite lacking other evidence, such as lithics or actual fossils, there is strong evidence for human animal butchery at the site in Romania, Curran said in the publication.

“(This new evidence) may lead other researchers to revisit similarly aged fossil collections from Europe that were not studied for traces of butchery because they were believed to only be of paleontological significance,” Pante said.

Reach Hana Pavelko at science@collegian.com or on Twitter @CSUCollegian.