As mentioned in yesterday's post, there have been some recent discoveries that are changing what we knew about the spread of our ancestors out of Africa and across Eurasia.
A new paper has disclosed that the site of Ubeidiya, in the Valley of the Jordan river has been dated to an age older than 1.9 million years. This is relevant because Acheulean tools, typical of Homo erectus have been found in those sediments, and this date is much older than previous estimates, pushing the first Out Of Africa event further back in time.
The paper: A. Matmon, et al., (2026). Complex exposure-burial history and Pleistocene sediment recycling in the dead sea rift with implications for the age of the Acheulean site of ‘Ubeidiya. Quaternary Science Reviews, Volume 378, 2026, 109871, ISSN 0277-3791, https://doi.org/10.1016/j.quascirev.2026.109871. 🔒
The Abstract reads as follows: "We present early Pleistocene burial ages of the ‘Ubeidiya Formation sediments in the Jordan Valley, a segment of the Dead Sea Rift Valley. A minimum age of ∼1.1 Ma is constrained both by paleomagnetic analysis and U-Pb dating of Melanopsis shells. Simple cosmogenic burial ages (i.e., one very long exposure period followed by one period of burial) calculated from the ratios of 26Al to 10Be and 10Be concentrations indicate ages of ∼3 Ma, contradicting the geological and paleomagnetic constraints as well as a reasonable age of the ‘Ubeidiya archeological site, as it contains human remains. A more sophisticated way of treating the results, by combining numerical modeling of cosmogenic nuclide build up during repeated burial-exposure cycles, paleomagnetic analysis (indicating reverse polarity) and a minimum burial age of 1.1 Ma set by U-Pb dating of Melanopsis shells, suggests two most probable time slots (1.19-1.77 and 1.93- 2.14 Ma) for the absolute age of the ‘Ubeidiya Formation. However, the skewed distribution of cosmogenic isotope burial ages, with a median age of 2.05 Ma, indicates a much higher probability of the older ages, most likely >1.9 Ma. The exposure-burial history that emerges from the model implies recycling of sediments previously deposited and buried in the rift valley, between 4.5 and 3.2 Ma, and subsequently exhumed, eroded, transported and then redeposited along the ‘Ubeidiya paleo lake shoreline."
Previous research had provided inconclusive dates, and used obscure methods. The consensus dates for the tools found there were between 1.2 and 1.6 million years. So this discovery pushes the first Out Of Africa migration back at least 300,000 years.
Furthermore, some previous dating of 3 Ma was due to the "recycling", that is the erosion of old strata, the transport and reburying of older sediment further down the valley making the sites seem older than they really are. However, the burial of sediments also preserved the information of magnetic field reversals which is a useful tool to date old strata ( magnetostratigraphy), the team also used radioactive decay of isotopes formed by cosmic rays in chert and quartz, and dating of snail shells using radioactive decay of Uranium to Lead. These three methods helped define the dating.
These dates make sense, because the earliest homo found in Eurasia, at Dmanisi, Georgia is slightly younger. This earlier presence of erectus in Israel, suggests that these erectus could have moved north towards Georgia, and also east, across Asia, reaching Eastern Asia (Indonesia and China) much earlier than previously expected (as we will see in my next post), and also, a possible continuation of their journey into America. They had almost 2 million years to do so before the arrival of Modern Humans in Eurasia.
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