Why didn't humans become prey?

Human evolution: Man - the born hunter

The researchers examined the dynamics of throwing and the anatomical structures involved in students who played baseball. They noticed three distinct anatomical differences between humans and chimpanzees: the long, flexible waist, which allows a much stronger rotation around the middle of the body; the humerus, which is less twisted in the longitudinal direction, and the shoulder socket pointing not upwards but to the side, whereby the rotation of the arm is superimposed on that of the body. These components significantly increase the range of motion and swing when throwing. In this way, much more elastic energy can be built up and transferred to the projectile than with an ape.

The team also discovered when these traits appeared in human evolution. Fossils of early and prehistoric humans show that the various adaptations did not all develop at the same time: A longer waist and a less twisted humerus were thus already exhibited by australopithecins, but the shoulder socket standing on the side was only added to the human species about two million years ago.

The extent to which the individual anatomical and physiological features developed from the start under conditions that favored more persistent running or more skillful throwing cannot be said. It is possible that some of these properties were initially created for other purposes - and it was only later that it turned out that they fit perfectly into the new context. The long waist, for example, was originally an adaptation to the upright gait. Later, the function was apparently added to give the throw even more speed by turning around the middle of the body.

However, Roach actually suspects selection forces that were directed towards the ability to throw as the mainspring behind the reconstruction of the shoulder two million years ago. Because with shoulders and arms like that, our ancestors could climb bad trees. Earlier hominins surely found refuge from predators in the branches in addition to food. "You only give up effortlessly climbing trees if you win something in return," speculates Roach. And it was probably not only the advantage that the rich animal food was now more accessible. Because with a well-aimed litter you could also drive away annoying predators that were threatening you or fighting your prey.

Early evidence of the hunt

But did early humans really routinely kill animals themselves two million years ago? Evidence for this is not easy to find. Stone tools and notches on animal bones from 2.6 million years ago suggest that hominins were at least dividing animals in this earlier phase. However, these could just as easily have been killed by predators or otherwise.

Up until a few years ago, the much younger wooden javelins from Schöningen provided the earliest undoubted evidence that humans hunted themselves, in this case horses. The eight slender spears, which were made from the trunks of young trees and had excellent throwing properties, were found by archaeologists in a lignite mine north of the Harz Mountains together with other hunting weapons and numerous animal bones in the 1990s. According to current calculations, they are around 300,000 years old. The finds from East Africa described at the beginning suggest that some groups of people already knew how to make spears with stone points at that time. A still controversial new study shifts the beginning of this technology for South Africa even further back, to about half a million years before our time.