Professor Francisco Ladeira, from the Department of Geography at the Institute of Geosciences at Unicamp, left last Saturday (21) for Jordan to participate in an international project that aims to identify the climatic and environmental conditions in which the first hominins that left Africa lived. towards Asia more than 2 million years ago. The team, led by Giancarlo Scardia, from the Institute of Geosciences and Exact Sciences at the Universidade Estadual Paulista "Julio de Mesquita Filho" (Unesp), will spend two weeks in the Zarqa Valley. The teacher will record the expedition on the Unicamp website.
Recently, the presence of a pre-erectus hominin was reported in Asia around 2 and a half million years ago, which corroborates the idea that the genus Homo found favorable conditions to occupy another continent characterized by different habitats. This movement towards Asia and its effects on homo sapiens are important for human evolution. The project aims to help understand how hominins from subtropical climates managed to adapt to more arid climates in the middle latitudes of Asia and what the habitats were like that allowed them to adapt and survive on the new continent.
According to Ladeira, Scardia has been working in the area for some time. The recent identification of hominin lithic material in China has posed a problem for the chronology of the departure of the first hominins from Africa. “In previous work, they identified material that dated approximately 2,5 million years ago. The most recent dates back to 2,1 million years. The central idea of this phase of the project is to return to the area and try to identify the environmental conditions in which these groups lived”, says the Unicamp researcher. He explains that “it is very unlikely that the current climate of the area would be receptive to migration of these groups from Africa to Asia and then to Europe. The key question is to identify the environmental conditions that allowed these groups to leave Africa and reach Asia.”
Ladeira was invited to work with paleoenvironments. The professor is a specialist in paleopedology, which is the study of ancient soils that record the past and the processes that led to current landscapes. Soil characteristics are the result of the interaction of all elements of the environment. “When we have a soil profile, we identify the result of the interaction of the biosphere with the lithosphere, the atmosphere and the hydrosphere”, explains the professor. Using the soil profile of Zarqa, which developed two million years ago, Ladeira will try to uncover the environmental conditions of that period — what those spheres were like. “From this analysis, it is possible to know what the average precipitation was, the average annual temperature, the vegetation cover… It is possible to draw a parallel between what conditions existed at that time, be it vegetation cover, climate, and the conditions in which these hominins managed to survive”, he explains. According to Ladeira, the conditions of that period were very different from current conditions.
In Zarqa, Ladeira will follow his normal field activity routine: opening the outcrop, collecting the soil sample and cleaning it to, finally, make a detailed description. “A 10 meter thick profile, for example, can be worked in up to three full days. We make a typical description of the pedology details, such as color and texture (relationship between sand and clay), and we observe the structures that this soil has,” he explains. Based on the description, samples are collected and analyzed in laboratories at Unicamp and Unesp. Physical and chemical analyzes will be carried out to identify granulometry — sand, silt, clay — and x-ray diffraction, which can provide inferences about the climate type of that period. A microscopy analysis will reveal the minerals that are in sand and silt size and the behavior of the clays — this helps to identify the amount of water available and whether there is a concentration of calcium carbonate or sulfate. “This set of information collected in the field and analyzes in laboratories will allow us to make inferences about the environmental conditions in force for more than two million years in the area, associated with the migration of these hominins”, explains Ladeira.
This will be Ladeira's first visit to Jordan, an area that has similar climates to places where the professor has worked. For the researcher, this will be an interesting experience. “It will be the first time that I will be in the field with some of these researchers. Exchanging experiences is something very enriching, which allows for growth,” she says. The expedition will include archaeologists Fábio Parenti, from the Federal University of Paraná, who worked for a long time with Niede Guidon at Pedra Furada — one of the oldest sites in Brazil, located in Piauí —, and Walter Alves Neves, from USP, who described Luzia — the oldest human remains in the national territory. Also participating are researchers from Unesp, the University of Jordan (Jordan), the Université Lyon 2, the Université de Lorraine (France), the Oregon State University (USA), the Argon Geochronology Laboratory (USA), the Geological Survey of Israel (Israel ) and the British Geological Survey (UK).
The Zarqa Valley is just a few dozen kilometers from Israel. Ladeira explains that researchers are not apprehensive about the war. “It’s not a very big or effective concern. My concern is whether and how the invasion of the Gaza Strip will occur and the reaction of Arab countries,” she says.
Read the article published by Revista Pesquisa Fapesp, in 2019:
Find in Jordan indicates that man may have left Africa 400 thousand years earlier than previously thought
Landing in Jordan
We left Brazil at 20:10 pm on Saturday night, the 21st, and arrived at the place where we will stay on Sunday night. It was almost 22 hours of travel. Everything was very peaceful – we traveled to Doha (Qatar) and from Doha to Amman (Jordan). What really caught our attention is that, when we were arriving in Amman, located very close to the Israeli border, it was possible to see some flashes, as if they were flashes – in reality, it was about the bombings on the Gaza Strip. We saw more flashes to the north, probably resulting from attacks on southern Lebanon. We are already staying in an apartment and have started the bureaucratic procedures.
This Monday, 23/10, we went very early to the Jordanian Department of Antiquities because we needed authorization to carry out the excavations planned for the field activity. We also pay a fee because there will be an employee from that department who will accompany us every day.
Next, we were at the Brazilian Embassy in Amman. Ambassador Marcos Fagundes do Nascimento received us. We report all activities planned during this period of field research. We must return to the embassy at the end of the expedition and there is the possibility that the ambassador will pay us a visit to the excavation area – in the Zarqa Valley. He was very receptive and said he could help us with any issue we faced during this period here in Jordan, including making contacts with other universities. And he also gave some tips and information regarding security, warning us to avoid going close to the border with Israel as much as possible. (By Francisco Ladeira)
Watch the video of the arrival of the plane with the expedition members in Amman and the explosions in the Gaza Strip:
Check out the first images captured by Ladeira:
