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It is easy to imagine that prehistoric hunting tools did not pack much of a punch compared to modern weaponry.

But scientists say that stone spear points used by our ancestors 500,000 years ago, are comparable to bullets that expand on impact because they create large 'wounds'.

They think that the use of stone tips had a large impact on human evolution because it allowed early humans to hunt large animals effectively.

Scientists at Arizona State University fired wooden and stone-tipped spears (pictured) - similar to those used by our ancestors 500,000 years ago -  into gelatine to examine the nature of the impact

Experts tested stone-tipped and sharpened wooden spears and found that both had the same penetrating power.

However, the stone point caused far more damage and was likened to the hollow-nose or 'dum-dum' bullet that expand on impact and are more destructive than regular bullets.

The study involved shooting six stone-tipped and six sharpened wooden spears into gelatine and examining the degree of penetration and damage they produced. 

Scientists fired stone-tipped spears into gelatine and found that created a significantly larger and wider 'wound' cavity. The cross-bow set up is pictured top, the gelatine bottom left and the target, bottom right

All were fired from a cross-bow with the same amount of force.

Scientists found that the stone-tipped spears created a significantly larger and wider 'wound' cavity.

Dr Jane Wilkins, of Arizona State University, said: 'Hafting a stone point to the end of a spear was an important innovation that changed life for Pleistocene humans. 

'Humans with stone-tipped spears were more likely to kill the game that they targeted, and were able to secure high quality food resources more frequently and regularly.' 

Up-grading spears with stone tips may have had a major impact on human evolution, according to the study, published in the journal Plos One.

The reserachers said that it took our ancestors time and effort to prepare and assemble a spear with a stone tip.

While they broke more frequently than sharpened wooden points - which could be dangerous when faced with a large angry animal – early humans seemed convinced that stone-tipped spears were a good idea, the experts said.

Benjamin Schoville said: 'Putting a fragile stone tip on a spear is risky, but we show that there are serious rewards in terms of both the size and shape of the wound created that made this innovation extremely worthwhile during our evolution.'

The researchers said that the manufacture of stone-tipped spears is thought to have been passed from generation to generation.

Scientists fired stone-tipped spears into gelatine and found that created a significantly larger and wider 'wound' cavity. In the same way, hollow-nosed bullets that expand on impact (pictured) are more destructive than regular bullets.

The use of stone tips had a large impact on human evolution because it allowed our ancestors to hunt large animals up to 500,000 years ago (illustrated)