In 2010, an international team of archaeologists led by Israel Hershkovitz of Tel Aviv University made a startling discovery: eight human teeth unearthed in a cave in central Israel, three of which are between 300,000 and 400,000 years old. Qesem Cave had been discovered in 2000, and excavations began in 2004. The teeth caused an uproar in the scientific community, as they were the oldest human teeth discovered.

Context and Controversy

After examining the teeth found in Qesem using X-rays and CT scans, the researchers compared them to other ancient teeth previously discovered around the world. They concluded the Qesem teeth were most similar to those that had been found in the Skhul and Qatzeh caves in northern Israel. Archaeologists widely accept that those teeth belonged to early modern humans. However, those teeth are only between 8,000 and 12,000 years old. An initial press release from Tel Aviv University announced the find, stating the teeth provided evidence Homo sapiens lived in the Levant region as long as 400,000 years ago. This disputed the prevailing theory that modern humans first evolved in Africa around 200,000 years ago.

Out of Africa

The generally accepted theory of human evolution holds that a single hominid species lived in Africa around 700,000 years ago. Over time, one group of these ancient hominids migrated into Europe and evolved separately, becoming Neanderthals. This group later became extinct. Ancient Homo sapiens, the earliest modern humans, evolved from the group that remained in Africa. Prior to the discovery of the teeth in Qesem, it was believed Homo sapiens began spreading from Africa into other parts of the world approximately 70,000 years ago. The age of the teeth present in the Israeli cave, however, may indicate Homo sapiens migrations began much earlier than previously believed.

Origin of Humans

The discovery of 400,000-year-old teeth in Israel opens up another possibility: modern man may have originated in Israel, rather than in Africa. However, for this to be plausible, the teeth would have to be conclusively identified as belonging to Homo sapiens, and that has not been done. The archaeologists who examined the teeth noted these isolated specimens came from at least six different individuals. While they have much in common with other ancient Homo sapiens teeth, they also share traits with Neanderthal teeth found in the area dating to between 60,000 and 150,000 years ago. Because there is much overlap in teeth variation among hominid species, scientists typically need several teeth from the same individual to conclusively identify that individual's species.

More Questions Than Answers

The identity of the ancient humans who possessed these teeth remains unresolved. Teeth of both Homo sapiens and Neanderthals contain a wide range of variation, and those found in Qesem overlap known variations in teeth belonging to members of both species. While they are Neanderthal-like in many respects, they lack key features thought to distinguish Neanderthal teeth from other ancient hominid teeth generally. Thus, some scientists believe the Qesem people may have been some previously unknown Homo sapiens-Neanderthal hybrid. Another possibility is that when Neanderthals migrated to Europe, this group separated and stayed in the Levant region, evolving apart from the European Neanderthals.