Being able to throw has allowed us to take over the world.

Hominids learnt how to throw around two million years ago, a skill which heavily influences much of what we are today.

You can go and look at any sport stadium across the world and you'll be able to witness humans incredible ability to throw. Especially when compared to our relatives the chimpanzees who can only throw at around 20mph against our speedy 90mph. This has lead many people to question how this ability evolved, and more importantly, why. 

Recent investigations into the fossils of our earliest ancestors show that Homo erectus underwent anatomical changes during its evolution which gave it its ability to throw. It might not seem much to us now, in a world where we mainly throw around balls or our mobile phones, but two million years ago being able to throw would have been the difference between life or death.

To try and understand this evolutionary development, researchers first looked at how humans throw today. They did this by recording a sample of athletes using motion capture cameras, with particular focus on their shoulders. This showed that the many ligaments and tendons that are involved in the movement of the shoulder are able to store a large amount of elastic energy, which can be released and used to force a projectile through the air. It would have been this ability to store elastic energy that would have put Homo erectus apart from Homo habilis and allowed it to throw at great speed.

Unlike other animals with large claws and teeth, humans have no natural weapons, and so required other methods of attack and defence. The ability to throw would have been an important step in our evolution, as it allowed us to defend ourselves against predators, as well as become predators ourselves. This change in diet to containing energy rich meat would have in turn also allowed for further changes in our biology, giving us the much larger bodies and brains that we have today.

It has also been suggested that this change in diet led to the division in labour between hunter and gatherers. This would have promoted a much more complex social hierarchy between the individuals of the group, a hierarchy that can still be seen in us humans today.

This hunting behaviour would have also been a deciding factor in our migration into new environments, which, without the ability to hunt, would not have previously been able to sustain our vegetarian lifestyles. These are all big parts of what makes us human, and just goes to show how one small adaptation could influence an entire organism’s future.

However, as is always the case with this kind of research, there are those who dispute the above findings. Susan Larson, whose work also focuses on shoulder anatomies has suggested that the above conclusions may have been drawn from an over interpretation of fossil evidence. She suggests that Homo erectus was not necessarily a very good thrower when compared with modern day human athletes, but rather a change in their anatomy gave them a much larger range of movements which would have allowed them to manipulate their environment more successfully.

There is always going to be dispute in this type of research, as very little is based on good solid fact, with most theories being developed and built up from one single piece of information.

However, what cannot be disputed is the importance of our ability to throw. Without being able to throw weapons we would not have been able to hunt, which would have prevented us evolving our large bodies and enormous brains, as well as stopping us from venturing into new environments and developing our complex social hierarchy.

So, next time you’re throwing something around, whether it be a ball or an inanimate object that’s annoyed you, think about the millions of years of evolution that’s gone into it, and try and appreciate it that little bit more.

What’s the best thing you’ve ever thrown around? Will this research influence how you think about chucking stuff about? Write below with comments or questions. 

If you'd like to read the full article published in nature, follow the link below:
http://www.nature.com/nature/journal/v498/n7455/full/nature12267.html