An article published in the journal “Scientific Reports” reports the attribution of a vertebra to the genus Homo with an estimated age of about 1.5 million years in the archaeological site of Ubeidiya, in today’s Israel. A team of researchers examined the fossil vertebra and compared it with other Eurasian hominin fossils from the Pleistocene period. The paleobiological differences led them to conclude that there were several migratory waves from Africa that correspond to the different stone working techniques discovered in archaeological studies.

The problem of the scarcity of fossils doesn’t only concern species dating back hundreds of millions of years ago but also some of the genus Homo dating back to less than two million years ago. This makes it difficult to reconstruct not only the relations between various species but also their migrations.

The Ubeidiya site is important because Pleistocene fossils of many animal species have been discovered there along with stone tools. Fossils discovered in the course of many different excavations between 1960 and 1999 are still being examined because they’re fragmentary and therefore difficult to attribute. One of these exams led to the attribution of a fossil vertebra with an age estimated at about 1.5 million years and discovered in 1966 to the genus Homo. The image (Courtesy Dr. Alon Barash, Bar-Ilan University) shows the vertebra in different views: top (a), rear (b), bottom (c), and front (d).

Other human fossils dating back about 1.8 million years discovered in today’s Georgia indicate that a wave of migration reached the Caucasus. The discussion was about whether there was a single migration from Africa or several waves. According to the authors of this study, there were several migratory waves with the consequence that the fossils discovered in Georgia and the Ubeidiya one belong to people who were part of two different waves.

The vertebra discovered at the Ubeidiya site belongs to an individual who was still growing, aged between 6 and 12 at the time of death. Having only one bone available, the information that can be obtained is limited, so the researchers haven’t attributed it to a species in particular. Its size suggests that the individual would have become very tall as an adult, too tall to be a Homo habilis.

According to the authors of this study, the paleobiological differences between this vertebra and the fossils discovered in Georgia are sufficient to establish that they were very different populations that migrated from Africa at different times. These could be populations of different species but there are even discussions on the taxonomy existing within the genus Homo and this makes the attributions more complex.

This new study is likely to spark discussions as well. It certainly shows that the history of humanity was already complex in the days of species such as Homo erectus / Homo ergaster. For this reason, the identification of a single bone such as the vertebra of the Ubeidiya site can add important information for the reconstruction of the most ancient migrations.