Our ancestor Homo erectus was already drawing geometric patterns half a million years ago. This is shown by carvings of zigzag patterns on the shell of a fossil freshwater mussel from Java. The scratches, the largest of which most resemble the letter M, were made on the shell about 500,000 years ago by humanoids. That is the conclusion of a group of 21 mostly Dutch archaeologists and earth scientists tomorrow in Nature .
The discovery of the patterns offers a new perspective on the evolution of human behavior. “Until now it was believed that making these kinds of engravings was the preserve of modern humans (Homo sapiens ) who lived in Africa from about 100,000 years ago,” says José Joordens, archaeologist at Leiden University and the lead author of the article. What the function or meaning of the engravings is, however, is a mystery.
Smart and handy
From the way the Homo erectus opened the freshwater mussels at the time, it turns out that this early hominin was quite smart and handy; He used a sharp object - probably a shark's tooth - to drill a hole in the mussel, exactly at the attachment point of the muscle that keeps the shell valves closed. The researchers found such holes in more than 50 of the more than 150 shells examined. The Homo erectus ate the mussel, and then made tools from the shells such as knives.
Archives
The engraved shell was not discovered on the beach of Java, but in the archives of the Naturalis museum in Leiden. Since the end of the 19th century, this museum has had hundreds of fossil shells and bones from the Trinil site on Java in Indonesia, once excavated there by the Limburg doctor and researcher Eugène Dubois. The zigzag patterns are only visible in grazing light, which must have been the reason that Dubois overlooked them himself. At the time the Java Man made the scratches, the shells were dark brown, and the patterns must have been visible as clear white stripes, the researchers write.
The Homo erectus belongs to the earliest hominids, after the Homo habilis who lived from 2.5 to 1.5 million years ago. His physique, stature, way of locomotion and even his brain volume of about a liter was very similar to ours. The Homo erectus lived first in Africa, later also in Asia and Europe. The first remains of the Homo erectus were found in Java – where the species is also known as Java Man.
Research
The scientists combined several research methods to explain the scratches and holes on the shells. They tried to copy the damage on fresh (live) mussels, and discovered that this was only possible by deliberately and hard working the shell with a sharp object. Using electron microscopy, they determined that the scratches had been made before the shell's weathering process began. The age of the fossil mussels was determined by combining different dating techniques, which made it possible to establish with certainty that the shells are between 430,000 and 540,000 years old. Finally, geochemical analyzes showed that the hominid bones and the shells from Dubois' collection belonged together, giving the Homo erectus could eventually be designated as the abstract artist.