A team of researchers from the University of Zurich has succeeded in confirming that the modern human brain arose approximately 1.5 to 1.7 million years ago in Africa, in the populations of the genus Homo that inhabited the current black continent. The cultural evolution and the brain structures would have occurred in the same period, making possible the development of the first forms of human language.
According to a press release , the researchers used computed tomography to examine the skulls of Homo fossils that lived in Africa and Asia between 1 and 2 million years ago. They then compared the fossil data with baseline data from great apes and humans.
They found that in the indicated period changes began to be observed in the size of the brain and in the regions of the frontal lobe that are responsible for planning and executing complex patterns of thought and action, including language. These characteristics would mark the origin of the contemporary human brain.
In addition, scientists think that biological and cultural evolution probably took place interdependently, it being possible that the earliest forms of human language also developed during this period. The research was recently published in the journal Science.
GREATER DATA ACCURACY
This is the first study that manages to analyze a wide variety of fossil skulls by means of computed tomography, thus being able to accurately determine dates and characteristics of brain evolution. In previous investigations, “footprints” or impressions left by the folds and grooves of the cranial structures had been used, making the accuracy of the data difficult.
Although the first populations of the genus Homo arose in Africa about 2.5 million years ago and their members already walked upright, their brains were only half their current size. The brain structures were similar to those that could be observed in apes, but at a certain point evolution began to take shape and the human brain began the way to its current configuration.
What are the characteristics that marked this development? In addition to the increase in size, the human brain began to clearly differentiate from that of the great apes when strong changes occurred in the location and organization of individual brain regions. It is precisely these changes that the specialists were able to appreciate in the fossil skulls used in their study.
BRAIN AND CULTURAL EVOLUTION
According to Marcia Ponce de León, lead author of the study, “the typical characteristics of humans are mainly found in those regions of the frontal lobe that are responsible for the coordination and execution of complex thoughts and activities. This logically includes language, “he said.
The expert explained that since these areas are significantly larger in the human brain, the adjacent brain regions moved further back, giving rise to the shape that identifies the contemporary brain.
At the same time, considering that during the period in which the evolution of the human brain took place, cultures in Africa also became more complex and diverse, as evidenced by the discovery of various types of stone tools, researchers believe that evolution biological and cultural was made practically at the same time and with a strong interdependence.
Consequently, it seems likely that around 1.7 million years ago, when the human brain began its path to its current form, primary forms of language would have begun to develop at the same time. In this way, human beings were preparing to change the history of the Earth forever and leave their strong mark, both for better and for worse, on the planet that shelters them to this day.
The primitive brain of early Homo . Marcia S. Ponce de León, Thibault Bienvenu, Assaf Marom, Silvano Engel, Paul Tafforeau, José Luis Alatorre Warren, David Lordkipanidze, Iwan Kurniawan, Delta Bayu Murti, Rusyad Adi Suriyanto, Toetik Koesbardiati and Christoph PE Zollikofer. Science (2021) .DOI: https: //doi.org/10.1126/science.aaz0032