Rat bones show climate helped early humans out of Africa through Israel

Researchers explained that the rodents, in order to survive at the time, would have needed more humid conditions, suggesting that the Judean Desert was greener and wetter.

By ROSSELLA TERCATIN, Jerusalem Post, JULY 27, 2021

https://www.jpost.com/archaeology/rat-bones-show-climate-helped-early-humans-out-of-africa-through-israel-675062

Ancient rat skull sheds light on the history of the Judean Desert.

(photo credit: DR. IGNACIO A. LAZAGABASTER)

Climate change creating favorable conditions for life, more than a specific ability to adapt to harsh conditions, supported early humans’ migration from Africa to Europe and Asia through the Levant, new research based on remains of an extinct poisonous rat found in Israel has suggested.

During excavations conducted in the Judean Desert in search of new Dead Sea Scrolls led by the Antiquities Authority (IAA), the archaeologists ran into a cave with a high number of bones belonging to an ancient rodent related to the eastern African crested rat, a long haired animal somewhat similar to a porcupine and equipped with a poisonous mane to fend off predators.

A team of Israeli and international researchers – led by Dr. Ignacio A. Lazagabaster of the University of Haifa and the Museum of Nature in Berlin with colleagues from Tel Aviv University, the Hebrew University of Jerusalem, Montpellier University, the Geological Survey of Israel and the IAA – analyzed the fossils, including some DNA that they were able to extract. The findings were published in the academic journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).

An image of the excavation in the Judean Desert cave. (Photo credit: Yuli Schwartz/IAA)

“We were able to extract DNA from the ancient bones in the Paleogenetic Laboratory at the Steinhardt Museum of Natural History – the earliest DNA extracted from bones in our region to date,” the authors explained. “Genetic and morphological analysis reveals that it is a subspecies of the crested rat that currently lives in East Africa.”

“These are very, very close animals, so if today this species lives in humid areas, chances are that even about 100,000 years ago the subspecies we found would have needed the same conditions,” they added, suggesting that at the time the Judean Desert was greener and wetter.

An illustration that combines the appearance of the area in the Judean Desert where the bones were found and an illustration of how it once looked based on the driest place where the mane rat is today, in Djibouti. (Photo credit: Aya Mark/Dr. Ignacio A. Lazagabaster)

According to the dating conducted by the researchers using radio-carbon and other methods, the bones found date back to a period between 120,000 and 42,000 years.

While the first human migration from Africa began as early as 1.8 million years ago, modern humans are thought to have left Africa and spread out to other areas of the world, passing through the territory of modern Israel starting around 100,000 years ago.

Scholars have been debating whether their ability to travel and cross deserts is to be attributed to more favorable climatic conditions compared to those presented by the same areas in modern times, or to specific skills developed by humans that allowed them to survive in harsher conditions.

“Since there cannot be any doubt that this species presented special technological capabilities and its modality of spreading happened through slow movements over similar climatic areas, we assume that the same African species reached the Judean Desert through an ancient climatic corridor,” the researchers noted. “It is likely that also humans, who migrated from Africa to the Levant at that time, were aided by the same ecological corridor.”