The carp skull on display comes from the natural history collection of Tel Aviv University's Steinhardt Museum of Natural History. Image source: Tel Aviv University
The remains of a giant carp (2 meters/6.5 feet long), analysed by the Hebrew University, Bar-Ilan University, Tel Aviv University in collaboration with Oranim College, Israel Institute of Oceanography and Limnology, Israel Natural History Museum, London and Mainz Johannes Gutenberg University marks the earliest signs of prehistoric humans dating back 780,000 years, about 600,000 years earlier than available data.
A careful analysis of the remains of a carp found at the archaeological site of Gesher Benot Ya'aqov (GBY) in Israel suggests that the fish was cooked about 780,000 years ago. Cooking is defined as the ability to process food by controlling the temperature at which it is heated, including a variety of methods, with the earliest evidence of cooking dating back to about 170,000 years ago. The question of when early humans began using fire to cook food has been the subject of much scientific discussion for more than a century. These findings shed new light on the question and were published in the journal Nature Ecology and Evolution.
Dr Zohar and Dr Prevost said: "This study demonstrates the enormous importance of fish in prehistoric human life, essential for their diet and economic stability. In addition, by studying the remains of fish found in Gesher Benot Ya'aqob, we were able to reconstruct the fish population of the ancient Hula Lake for the first time and show that there are fish in the lake that have become extinct over time. ”
Illustration of ancient humans developing and cooking Luciobarbus longiceps (Ella Maru) on the shores of Hula Ancient Lake (illustration by Ella Maru). Image source: Tel Aviv University
"These species include giant barbed fish (carp-like fish) up to 2 meters long. The large number of fish remains found at the site testifies to the fact that early humans often ate them, who developed special cooking techniques. These new findings not only illustrate the importance of freshwater habitats and the fish they contain for prehistoric human survival, but also the ability of prehistoric humans to control fire to cook food, and the benefits of knowing about cooking fish before eating it. ”
In this study, the researchers focused on the pharyngeal teeth of carps (used to grind hard foods such as shells). These teeth are found in large quantities in different archaeological formations of the site. By studying the crystal structure that forms tooth enamel, which increases in size due to heat, the researchers were able to show that fish caught in the ancient Hula Lake near the site were exposed to temperatures suitable for cooking, rather than simply being burned by spontaneous fire.
So far, evidence of cooking with fire has been limited to sites much later than GBY sites — about 600,000 years old, most of which are related to the emergence of our own species, Homo sapiens.
Professor Goren-Inbar added: "The fact that fish cooking was evident during the long and uninterrupted settlement of the site shows that the tradition of cooking food continues. This is another ability of Acheulian hunter-gatherers active in the ancient Hula Valley region in a series of discoveries associated with high cognitive abilities. ”
"These groups are very familiar with their environment and the various resources they provide to them. In addition, this shows that they have extensive knowledge of the life cycles of different plant and animal species. Acquiring the skills needed to cook food marks a significant evolutionary advance, as it provides an additional means of optimizing the use of existing food resources. Cooking may not even be limited to fish, but also include a variety of flora and fauna. ”
Professors Hershkovitz and Dr. Zohar noted that the shift from eating raw to cooked food has had a huge impact on human development and behavior. Eating cooked food reduces the amount of energy it takes to break down and digest food, allowing other body systems to develop. It also causes changes in the structure of the human jaw and skull.
Location of the archaeological site of Gesher Benot Ya'aqov (GBY) on the African House of Erectus route. Image source: Tel Aviv University
This change frees humans from the daily intensive work of finding and digesting raw foods, providing them with free time to develop new social and behavioral systems. Some scientists believe that eating fish is a milestone in the evolution of human cognition, providing a central catalyst for the development of the human brain.
They claim that eating fish makes us human. Even today, components such as omega-3 fatty acids, zinc, iodine, etc. in fish meat are known to help brain development a lot.
The team believes that the location of freshwater areas, some of which are in areas that have long dried up and become arid deserts, determined the routes of early human migration from Africa to the Levant and beyond. Not only do these habitats provide the area with drinking water and attract animals, but fishing in shallow water is a relatively simple and safe task with high nutritional returns.
The team believes that developing fish in freshwater habitats is the first step for prehistoric humans to move out of Africa. Early humans began eating fish about 2 million years ago, but the culinary fish found in this study represents a true revolution in the Acheulian diet and is an important foundation for understanding the relationship between humans, the environment, climate, and migration. Reconstructing the history of early humans.
It should be noted that Professor Nira Alperson-Afil of the BIU first found evidence of the use of fire at the site - the oldest evidence of this kind in Eurasia. "Using fire is an act, characteristic of the entire settlement of the site," she explained. "This affects the spatial organization of the venue and the activities that take place there, which revolve around the fireplace." Alperson-Afil's study of fire at the site was revolutionary at the time, showing that fire was used hundreds of thousands of years earlier than previously thought.
HU's Goren-Inbar added that GBY's archaeological site documents the continuity of repeated settlement by hunter-gatherer groups along the shores of ancient Huraa that lasted tens of thousands of years.
Luciobarbus longiceps skull. Image source: Tel Aviv University
"These groups took advantage of the rich resources provided by the ancient Hula River Valley, leaving behind a long-term sedentary continuum with more than 20 layers of settlement," explains Goren-Inbar. Excavations at the site have revealed the material culture of these ancient humans, including flint, basalt and limestone tools, as well as their food sources, characterized by the rich variety of plants along the lake and its shores (including fruits, nuts and seeds) and many medium and large land mammals.
Dr Jens Najorka, from the Natural History Museum in London, explains: "In this study, we used geochemical methods to determine changes in the size of tooth enamel crystals due to exposure to different cooking temperatures. When they are charred by fire, it is easy to recognize drastic changes in the size of enamel crystals, but it is more difficult to identify changes caused by cooking at temperatures between 200 and 500 degrees Celsius. ”
"The experiments I conducted with Dr. Zohar allowed us to determine the changes caused by low-temperature cooking. We don't know how the fish are cooked, but given the lack of evidence of exposure to high temperatures, it's clear that they weren't cooked directly in the fire or thrown into the fire as garbage or burning material. ”
Dr. Guy Sisma-Ventura of the Israel Institute of Oceanography and Limnology and Professor Thomas Tütken of Johannes Gutenberg University in Mainz were also part of the research team, which analyzed the isotopic composition of oxygen and carbon in the enamel of fish teeth.
"This isotopic study is a real breakthrough because it allows us to reconstruct the hydrological conditions of this ancient lake throughout the season, thus determining that fish are not a seasonal economic resource, but are caught and eaten year-round." As a result, fish provides a constant source of nutrients, reducing the need for seasonal migration. ”